build: package universal Windows runtime and verify automatic CPU fallback

.gitignore

@@ -8,6 +8,8 @@ dist/
 __pycache__/
 /apps/desktop/src-tauri/gen/
 /apps/desktop/src-tauri/resources/searchi-gemma-worker*
+/apps/desktop/src-tauri/resources/vulkan-1.dll
+/apps/desktop/src-tauri/resources/VULKAN-LICENSE.txt
 /apps/desktop/src-tauri/resources/embeddinggemma2/
 /apps/desktop/src-tauri/resources/media-runtime/bin/
 /apps/desktop/src-tauri/icons/android/

README.md

@@ -142,6 +142,10 @@ How quickly a folder becomes searchable depends on its size and contents.
 The desktop keeps its search model warm for subsequent searches.
 Use **Reindex** after adding or changing files in an indexed folder.
 
+searchi automatically chooses supported graphics acceleration when available
+and falls back to CPU when it cannot use it. You do not need a graphics
+development toolkit. Hardware and release validation are still in progress.
+
 ## Private by design
 
 You choose the folders to index. By default, file contents, previews and search

crates/searchi-semantic/native/worker.cpp

@@ -48,6 +48,8 @@ class Encoder {
     }
     bool open(bool gpu) {
         auto mp = llama_model_default_params();
+        static ggml_backend_dev_t cpu_devices[] = {nullptr};
+        if (!gpu) mp.devices = cpu_devices;
         mp.n_gpu_layers = gpu ? 999 : 0;
         mp.progress_callback = [](float,void *) {return true;};
         model = llama_model_load_from_file(model_path.c_str(),mp);
@@ -55,6 +57,7 @@ class Encoder {
         auto cp = llama_context_default_params();
         cp.n_ctx = context_tokens; cp.n_batch = context_tokens; cp.n_ubatch = context_tokens;
         cp.n_seq_max = 1; cp.kv_unified = true; cp.embeddings = true;
+        cp.offload_kqv = gpu; cp.op_offload = gpu;
         cp.pooling_type = LLAMA_POOLING_TYPE_MEAN;
         cp.n_threads = threads; cp.n_threads_batch = threads;
         context = llama_init_from_model(model,cp);
@@ -327,6 +330,16 @@ int main(int argc, char ** argv) {
         require(!path.empty() && threads >= 1 && threads <= 8,"Model path required; threads must be 1–8");
         require(device == "cpu" || device == "auto","Device must be cpu or auto");
         bool force_cpu = std::getenv("SEARCHI_FORCE_CPU") && std::string(std::getenv("SEARCHI_FORCE_CPU")) == "1";
+        // Disable backend registration before llama initializes its registry.
+        // A GPU-capable distribution can therefore be tested on CPU without
+        // probing/enabling the Vulkan provider in the Windows VM.
+        if (force_cpu || device == "cpu") {
+#ifdef _WIN32
+            require(_putenv_s("GGML_DISABLE_VULKAN", "1") == 0, "Cannot disable Vulkan for CPU startup");
+#else
+            require(setenv("GGML_DISABLE_VULKAN", "1", 1) == 0, "Cannot disable Vulkan for CPU startup");
+#endif
+        }
         Encoder encoder(path,threads,device == "auto" && !force_cpu);
         std::cout << json({{"ready",true},{"model","google/embeddinggemma-2"},{"dimensions",dimensions},
             {"device",encoder.device},{"threads",threads},{"runtime",SEARCHI_LLAMA_TAG},{"media_supported",true},{"code_query_supported",true}}).dump() << '\n' << std::flush;

crates/searchi-semantic/src/gemma.rs

@@ -78,6 +78,27 @@ impl Drop for GemmaEmbedder {
     }
 }
 
+#[derive(Debug)]
+struct StartupTransportFailure(String);
+impl std::fmt::Display for StartupTransportFailure {
+    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        formatter.write_str(&self.0)
+    }
+}
+impl std::error::Error for StartupTransportFailure {}
+
+/// Retry only process/transport failure, never an incompatible protocol or model.
+fn start_with_cpu_fallback<T>(cpu: bool, mut start: impl FnMut(bool) -> Result<T>) -> Result<T> {
+    match start(cpu) {
+        Err(error) if !cpu && error.downcast_ref::<StartupTransportFailure>().is_some() => {
+            start(true).with_context(|| {
+                format!("CPU initialization failed after automatic worker startup failure: {error}")
+            })
+        }
+        result => result,
+    }
+}
+
 impl GemmaEmbedder {
     /// Load the verified Google model and explicitly supplied local worker.
     /// Production selects available acceleration with CPU fallback. Tests set
@@ -113,7 +134,16 @@ impl GemmaEmbedder {
         );
         let force_cpu = std::env::var("SEARCHI_FORCE_CPU").is_ok_and(|value| value == "1");
         let cpu = force_cpu || matches!(device, Device::Cpu);
-        let mut command = Command::new(&worker);
+        start_with_cpu_fallback(cpu, |cpu| {
+            Self::start_verified(&model_dir, &worker, threads, cpu)
+        })
+    }
+
+    // Both attempts share the already validated model/worker paths. CPU fallback
+    // does not repeat the expensive hash check or weaken the handshake contract.
+    fn start_verified(model_dir: &Path, worker: &Path, threads: usize, cpu: bool) -> Result<Self> {
+        let model = model_dir.join(MODEL_FILE);
+        let mut command = Command::new(worker);
         command
             .args(["--model"])
             .arg(model)
@@ -132,9 +162,14 @@ impl GemmaEmbedder {
             use std::os::windows::process::CommandExt;
             command.creation_flags(0x08000000); // CREATE_NO_WINDOW
         }
-        let mut child = command.spawn().context("Cannot start local Gemma worker")?;
+        let mut child = command.spawn().map_err(|error| {
-        let stdin = child.stdin.take().context("Worker stdin missing")?;
+            StartupTransportFailure(format!("Cannot start local Gemma worker: {error}"))
-        let stdout = child.stdout.take().context("Worker stdout missing")?;
+        })?;
+        let (Some(stdin), Some(stdout)) = (child.stdin.take(), child.stdout.take()) else {
+            let _ = child.kill();
+            let _ = child.wait();
+            anyhow::bail!("Gemma worker protocol pipes missing");
+        };
         let (sender, responses) = mpsc::sync_channel(1);
         thread::spawn(move || {
             let mut reader = BufReader::new(stdout);
@@ -151,7 +186,16 @@ impl GemmaEmbedder {
             other => {
                 let _ = child.kill();
                 let _ = child.wait();
-                anyhow::bail!("Gemma worker did not initialize: {other:?}");
+                // Malformed/oversized JSON is a protocol violation, not evidence
+                // that hardware acceleration failed. Do not mask it with retry.
+                if matches!(&other, Ok(Err(error)) if error.starts_with("Invalid Gemma worker JSON:") || error == "Gemma worker response exceeds protocol byte budget")
+                {
+                    anyhow::bail!("Invalid Gemma worker startup protocol: {other:?}");
+                }
+                return Err(StartupTransportFailure(format!(
+                    "Gemma worker did not initialize: {other:?}"
+                ))
+                .into());
             }
         };
         let info: WorkerInfo = match serde_json::from_value(ready) {
@@ -181,8 +225,8 @@ impl GemmaEmbedder {
             info,
             healthy: true,
             force_cpu: cpu,
-            model_dir,
+            model_dir: model_dir.to_path_buf(),
-            worker_path: worker,
+            worker_path: worker.to_path_buf(),
             projector_verified: false,
             query_profile: None,
         })
@@ -666,6 +710,73 @@ fn verify_artifact(path: &Path, bytes: u64, sha: &str) -> Result<()> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    #[test]
+    fn automatic_startup_transport_failure_retries_cpu_once() {
+        let mut attempts = Vec::new();
+        let result = start_with_cpu_fallback(false, |cpu| {
+            attempts.push(cpu);
+            if cpu {
+                Ok("cpu ready")
+            } else {
+                Err(StartupTransportFailure("worker closed its output before ready".into()).into())
+            }
+        })
+        .unwrap();
+        assert_eq!(result, "cpu ready");
+        assert_eq!(attempts, [false, true]);
+    }
+
+    #[test]
+    fn startup_failure_never_loops_or_retries_explicit_cpu() {
+        for cpu in [false, true] {
+            let mut attempts = Vec::new();
+            let result: Result<()> = start_with_cpu_fallback(cpu, |selected_cpu| {
+                attempts.push(selected_cpu);
+                Err(StartupTransportFailure("worker exited".into()).into())
+            });
+            let error = format!("{:#}", result.unwrap_err());
+            assert_eq!(attempts, if cpu { vec![true] } else { vec![false, true] });
+            assert!(error.contains("worker exited"));
+            if !cpu {
+                assert!(error.contains("CPU initialization failed"));
+            }
+        }
+    }
+
+    #[test]
+    fn malformed_startup_protocol_is_not_retried() {
+        let mut attempts = 0;
+        let result: Result<()> = start_with_cpu_fallback(false, |_| {
+            attempts += 1;
+            let mut response = BufReader::new(&b"not JSON\n"[..]);
+            let error = read_response(&mut response).unwrap_err();
+            assert!(error.starts_with("Invalid Gemma worker JSON:"));
+            anyhow::bail!("Invalid Gemma worker startup protocol: {error}");
+        });
+        assert!(result.unwrap_err().to_string().contains("startup protocol"));
+        assert_eq!(attempts, 1);
+    }
+
+    #[test]
+    fn incompatible_startup_contract_is_not_retried() {
+        let mut attempts = 0;
+        let result: Result<()> = start_with_cpu_fallback(false, |_| {
+            attempts += 1;
+            let handshake = json!({"ready":true,"model":"other-model","dimensions":768,"device":"cpu","threads":1,"runtime":"other-runtime"});
+            let info: WorkerInfo = serde_json::from_value(handshake)?;
+            ensure!(
+                info.model == "google/embeddinggemma-2",
+                "Gemma worker handshake violates configured model/device contract"
+            );
+            Ok(())
+        });
+        assert!(result
+            .unwrap_err()
+            .to_string()
+            .contains("model/device contract"));
+        assert_eq!(attempts, 1);
+    }
+
     #[test]
     fn old_text_worker_handshake_does_not_claim_media_support() {
         let mut handshake = json!({"ready":true,"model":"google/embeddinggemma-2","dimensions":768,"device":"cpu","threads":1,"runtime":"b11461-no-logits-v1"});

docs/BUILDING.md

@@ -89,8 +89,11 @@ search starts a model process; the desktop retains a prewarmed query worker.
 Normal distribution worker builds and staging default to `auto`: Metal on
 macOS, Vulkan on Windows/Linux, with CPU fallback in the same application.
 Users do not choose a CPU/GPU edition or rebuild for their graphics card.
-Windows/Linux build machines need the Vulkan SDK including `glslc`; absence
+Windows/Linux build machines need the Vulkan SDK including `glslc`. Windows
-fails release preparation instead of quietly generating a CPU-only runtime.
+x64 provisioning now downloads the pinned, checksum-verified official SDK into
+the workspace using copy-only mode; it does not install drivers or change the
+system environment. Linux builders provision their distro's Vulkan development
+tools. Missing required tools fail release preparation rather than omitting GPU.
 The compilation SDK is not an end-user requirement. Explicit `--backend cpu`
 commands in the VM development sections are internal test configurations.
 
@@ -133,7 +136,9 @@ matching-architecture Google worker, FFmpeg/FFprobe and notices. It excludes
 model caches, local settings and indexes. `PACKAGE.json` records SHA-256 for
 each included file. Extract the entire archive before launching `searchi.exe`.
 First launch uses normal verified model setup. WebView2 and the applicable
-Microsoft C++ runtime remain Windows prerequisites.
+Microsoft C++ runtime remain Windows prerequisites. The Windows archive includes
+the verified Vulkan loader DLL and its license; GPU availability is detected at
+runtime, with CPU fallback. The SDK is used only to compile the app.
 
 This is an unsigned development archive, not a production installer. Native
 launch, clean-machine dependencies, upgrades and signatures must still be

docs/ROADMAP.md

@@ -53,6 +53,12 @@ Status: implementation started; no production release yet. Windows VM tests use
   fallback; missing Vulkan/glslc fails configuration rather than hiding GPU loss.
 - [ ] Provision release-build GPU SDKs and verify one hardware-detecting package
   per OS/architecture, including missing-driver fallback and dependency closure.
+- [x] Windows-x64 official pinned SDK copied into workspace with verified cache
+  provenance; universal CPU/Vulkan worker and embedded-frontend desktop built.
+- [x] Real Windows archive integrity, packaged decoder startup and auto-mode
+  CPU inference with a controlled no-GPU-provider registry; Google CPU parity.
+- [ ] Actual missing/incompatible GPU drivers, precision, device loss and memory
+  pressure on release hardware; native GUI and clean-machine archive launch.
 - [x] Windows desktop archive packager includes explicit runtime/helper files
   and notices, checks architecture and records per-file checksums; excludes
   model caches and user data. Controlled packaging regression tests pass.

docs/SEMANTIC.md

@@ -40,6 +40,13 @@ must have the relevant compilation SDK. Missing Vulkan/glslc now fails the
 normal build rather than silently omitting acceleration. Actual GPU parity,
 loader/dependency packaging and no-driver CPU fallback still require evidence.
 
+Windows x64 build scripts provision the pinned official Vulkan SDK locally,
+verify its provenance and stage the app-local loader with its notice. Forced
+CPU startup disables Vulkan registration before the backend registry initializes;
+CPU contexts disable device-operation offload. Automatic startup transport
+failure now restarts once on CPU without weakening model/protocol validation.
+GPU inference failure also retains the bounded existing CPU retry.
+
 | Artifact | Bytes | SHA256 |
 | --- | ---: | --- |
 | embeddinggemma-2-Q8_0.gguf | 309,855,456 | 2188ac1deca4b77dffefd603c2776a9d76d9d74ec01841392982ebb840b09135 |

docs/VALIDATION.md

@@ -7,19 +7,34 @@ and `SEARCHI_FORCE_CPU=1`.
 
 ## Current integration checkpoint (2026-10-12)
 
-The Windows archive packager has two controlled Python regressions: complete
+The Windows-x64 universal worker built with CPU and Vulkan enabled, using the
-required file collection with checksum verification and user-settings exclusion,
+pinned official LunarG 1.4.363.0 SDK (download hash and publisher signature
-and mismatched worker architecture preserving the previous archive. Both pass.
+verified). Copy-only installation and later provenance/swap validation ran in
-An actual CPU-only Tauri embedded-frontend Release build has been started;
+the workspace; no driver/registry installation or GPU inference occurred.
-the embedded-frontend Release application build completed in 7m 25s. CPU-only
+The desktop embedded-frontend Release build completed and was rebuilt with
-describes its VM test context, not a supported end-user edition. The normal
+startup fallback. The generated unsigned Windows archive includes its worker,
-worker build/staging defaults are now auto and require GPU compilation support
+app-local Vulkan loader, FFmpeg/FFprobe and named notices. Six packaging
-alongside CPU fallback. The previously staged CPU worker remains an internal
+regressions verify exact archived-byte hashes, changes during copying, notices,
-test artifact; archive creation, automatic-runtime dependency packaging, native
+architecture mismatch, failed-write cleanup and preservation of previous output.
-launch outside the source tree and clean-machine installation remain unverified.
+
-Actual `auto` configuration correctly rejected this VM's missing Vulkan library,
+The actual extracted package's worker was requested in `auto` mode, with
-headers and `glslc`; no GPU-capable worker/package is claimed. Both staging
+`SEARCHI_FORCE_CPU` absent and Vulkan disabled only in that child. It detected
-regressions still pass using explicit internal CPU test configuration.
+a CPU-only backend registry and produced a real normalized 768d code vector;
+its decoder started successfully. All 13 recorded package files passed hash
+checks. [Raw package evidence](evidence/windows-package-cpu-fallback.json).
+The final local archive is 140,971,051 bytes; its digest is included in that
+evidence. It has not been published as a production release.
+This is controlled no-provider fallback, not a physical GPU/driver test or
+native GUI/clean-machine certification. Actual GPU precision/parity, native
+application interaction, signed installers and other OS/architecture gates stay open.
+Two real code tests and existing Google text-reference/tail parity passed on
+the GPU-capable worker's forced-CPU path. Four startup regressions check one
+CPU retry after automatic startup transport failure while preserving invalid
+protocol/model rejection and explicit-CPU behavior. Eight Vulkan-provisioning
+tests verify cache provenance, bounds, atomic loader reuse and SDK swap rollback.
+The integrated workspace and native desktop tests passed, along with strict
+all-target Rust Clippy, frontend Release build and formatting checks. Gitea
+Actions remain disabled at Karl's request.
 
 Offline staging now verifies the native license and every bundled Google asset
 before modifying resources. Two Python regressions verify missing-model rejection

docs/evidence/windows-package-cpu-fallback.json

@@ -0,0 +1,12 @@
+{
+  "architecture": "x86_64",
+  "verified_files": 13,
+  "archive_sha256": "7fa9ccc87ee4fdd0d539898853c47e5b125b42518337a4a2d8393e98c54fb8b8",
+  "worker_requested_device": "auto",
+  "worker_actual_device": "cpu",
+  "no_gpu_condition": "GGML_DISABLE_VULKAN=1 only in child; SEARCHI_FORCE_CPU absent",
+  "worker_startup_query_and_exit_ms": 2509.7244000062346,
+  "query_dimensions": 768,
+  "decoder": "ffprobe version n9.0.2-27-g7e93014c5b-20261012 Copyright (c) 2007-2026 the FFmpeg developers",
+  "scope": "Real packaged worker default-mode CPU fallback with disabled provider; no GPU, native UI or clean-machine certification"
+}

tools/embeddinggemma2/build_runtime.py

@@ -22,6 +22,11 @@ def main():
     args = parser.parse_args()
     if not 1 <= args.jobs <= 16:
         parser.error("jobs must be 1–16")
+    vulkan_loader = None
+    if os.name == "nt" and args.backend in {"auto", "vulkan"}:
+        from provision_vulkan import provision
+        sdk, vulkan_loader = provision()
+        os.environ["VULKAN_SDK"] = str(sdk)
     source = ROOT / ".searchi/references/llama.cpp"
     build = ROOT / ".searchi/runtime" / args.backend
     if not source.exists():
@@ -51,6 +56,9 @@ def main():
          "-DCMAKE_BUILD_TYPE=Release", f"-DLLAMA_CPP_DIR={source}",
          f"-DSEARCHI_ACCELERATION={args.backend}"])
     run([cmake_exe, "--build", build, "--config", "Release", "--parallel", args.jobs])
+    if vulkan_loader:
+        for name in ["vulkan-1.dll", "VULKAN-LICENSE.txt"]:
+            shutil.copy2(vulkan_loader / name, build / "Release" / name)
     print(f"Runtime build complete: {build}")
 
 

tools/embeddinggemma2/package_smoke.py

@@ -0,0 +1,84 @@
+"""Verify a real Windows package and its default-mode no-GPU CPU inference.
+
+No desktop UI or GPU inference is exercised. The upstream Vulkan provider is
+disabled only inside the child process to expose a genuinely CPU-only registry.
+"""
+import argparse
+import hashlib
+import json
+import math
+import os
+from pathlib import Path
+import subprocess
+import tempfile
+import time
+import zipfile
+
+ROOT = Path(__file__).resolve().parents[2]
+
+
+def main():
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--archive", type=Path, default=ROOT / ".searchi/packages/searchi-windows.zip")
+    parser.add_argument("--models", type=Path, default=ROOT / ".searchi/models/embeddinggemma2")
+    parser.add_argument("--output", type=Path, default=ROOT / ".searchi/packages/smoke.json")
+    args = parser.parse_args()
+    manifest = json.loads(Path(__file__).with_name("model-manifest.json").read_text())
+    model = args.models / manifest["files"][0]["path"]
+    with model.open("rb") as stream:
+        assert hashlib.file_digest(stream, "sha256").hexdigest() == manifest["files"][0]["sha256"]
+    parent = ROOT / ".searchi/packages"
+    parent.mkdir(parents=True, exist_ok=True)
+    with tempfile.TemporaryDirectory(prefix="smoke-", dir=parent) as folder:
+        target = Path(folder).resolve()
+        assert target.is_relative_to(parent.resolve())
+        with zipfile.ZipFile(args.archive) as archive:
+            package = json.loads(archive.read("PACKAGE.json"))
+            for record in package["files"]:
+                path = target / record["path"]
+                assert path.resolve().is_relative_to(target)
+                data = archive.read(record["path"])
+                assert len(data) == record["bytes"]
+                assert hashlib.sha256(data).hexdigest() == record["sha256"]
+                path.parent.mkdir(parents=True, exist_ok=True)
+                path.write_bytes(data)
+        environment = dict(os.environ, GGML_DISABLE_VULKAN="1")
+        environment.pop("SEARCHI_FORCE_CPU", None)
+        started = time.perf_counter()
+        worker = subprocess.Popen([str(target / "searchi-gemma-worker.exe"), "--model", str(model),
+            "--threads", "1", "--device", "auto"], stdin=subprocess.PIPE, stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE, text=True, encoding="utf-8", env=environment,
+            creationflags=subprocess.CREATE_NO_WINDOW)
+        request = json.dumps({"op": "code_query", "text": "retry failed requests with exponential backoff"}) + "\n"
+        try:
+            stdout, stderr = worker.communicate(request, timeout=120)
+        except BaseException:
+            worker.kill()
+            worker.wait(timeout=10)
+            raise
+        assert worker.returncode == 0, stderr
+        worker_duration_ms = (time.perf_counter()-started)*1000
+        hello, result = [json.loads(line) for line in stdout.splitlines()]
+        assert hello["ready"] and hello["device"] == "cpu" and result["device"] == "cpu" and result["ok"]
+        vector = result["vectors"][0]
+        assert len(vector) == 768 and all(math.isfinite(x) for x in vector)
+        assert abs(sum(x*x for x in vector) - 1) < 0.0001
+        decoder = subprocess.run([str(target / "media-runtime/bin/ffprobe.exe"), "-version"],
+            env=dict(os.environ, SEARCHI_FORCE_CPU="1"), capture_output=True, text=True,
+            creationflags=subprocess.CREATE_NO_WINDOW, check=True, timeout=30)
+        with args.archive.open("rb") as stream:
+            archive_checksum = hashlib.file_digest(stream, "sha256").hexdigest()
+        report = {"architecture": package["architecture"], "verified_files": len(package["files"]),
+            "archive_sha256": archive_checksum,
+            "worker_requested_device": "auto", "worker_actual_device": hello["device"],
+            "no_gpu_condition": "GGML_DISABLE_VULKAN=1 only in child; SEARCHI_FORCE_CPU absent",
+            "worker_startup_query_and_exit_ms": worker_duration_ms,
+            "query_dimensions": len(vector), "decoder": decoder.stdout.splitlines()[0],
+            "scope": "Real packaged worker default-mode CPU fallback with disabled provider; no GPU, native UI or clean-machine certification"}
+        args.output.parent.mkdir(parents=True, exist_ok=True)
+        args.output.write_text(json.dumps(report, indent=2)+"\n")
+        print(json.dumps(report, indent=2))
+
+
+if __name__ == "__main__":
+    main()

tools/embeddinggemma2/provision_vulkan.py

@@ -0,0 +1,173 @@
+"""Pinned Windows-x64 Vulkan build tools and app-local loader, no GPU execution.
+
+SDK copy-only mode does not install drivers or change system environment/registry.
+Checksums are from https://vulkan.lunarg.com/sdk/home/ (2026-10-12).
+"""
+import hashlib
+import json
+import os
+from pathlib import Path
+import platform
+import subprocess
+import urllib.request
+import uuid
+import zipfile
+
+ROOT = Path(__file__).resolve().parents[2]
+VERSION = "1.4.363.0"
+SDK_SHA = "94a82d378f7a5e3e54c9db7d2fb7016af136e14ac0a18dbf0f2f67a36352d141"
+LOADER_SHA = "a25a927aa8b9f0371048f1861cf88ac3b9bc9b1fb332c42d897c8ab32695769a"
+
+
+def digest(path):
+    with path.open("rb") as stream:
+        return hashlib.file_digest(stream, "sha256").hexdigest()
+
+
+def download(path, remote, expected, limit):
+    if path.is_file() and digest(path) == expected:
+        return
+    temporary = path.with_suffix(path.suffix + ".partial")
+    url = f"https://sdk.lunarg.com/sdk/download/{VERSION}/windows/{remote}?Human=true"
+    try:
+        request = urllib.request.Request(url, headers={"User-Agent": "searchi-build-tooling/1.0"})
+        with urllib.request.urlopen(request, timeout=120) as response, temporary.open("wb") as output:
+            count = 0
+            while block := response.read(1024 * 1024):
+                count += len(block)
+                if count > limit:
+                    raise ValueError("Vulkan download exceeds size ceiling")
+                output.write(block)
+        if digest(temporary) != expected:
+            raise ValueError("Vulkan download checksum mismatch")
+        os.replace(temporary, path)
+    finally:
+        temporary.unlink(missing_ok=True)
+
+
+def sdk_files(sdk):
+    required = [sdk / "Bin/glslc.exe", sdk / "Lib/vulkan-1.lib",
+                sdk / "Include/vulkan/vulkan.h", sdk / "Include/vulkan/vulkan_core.h"]
+    if not all(path.is_file() for path in required):
+        raise RuntimeError("SDK copy did not provide required tools and headers")
+    files = set(required)
+    for directory in [sdk / "Include/vulkan", sdk / "Include/vk_video"]:
+        files.update(path for path in directory.rglob("*") if path.is_file())
+    files.update((sdk / "Bin").glob("*.dll"))
+    if len(files) > 4096:
+        raise ValueError("Vulkan SDK manifest exceeds file count ceiling")
+    return {path.relative_to(sdk).as_posix(): digest(path) for path in sorted(files)}
+
+
+def sdk_verified(sdk):
+    manifest = sdk / "searchi-provenance.json"
+    try:
+        if manifest.stat().st_size > 1024 * 1024:
+            return False
+        value = json.loads(manifest.read_text(encoding="utf-8"))
+        return (value.get("version") == VERSION and value.get("installer_sha256") == SDK_SHA
+                and value.get("files") == sdk_files(sdk))
+    except (OSError, ValueError, RuntimeError, TypeError, AttributeError):
+        return False
+
+
+def write_sdk_provenance(sdk):
+    value = {"version": VERSION, "installer_sha256": SDK_SHA, "files": sdk_files(sdk)}
+    temporary = sdk / "searchi-provenance.json.partial"
+    try:
+        temporary.write_text(json.dumps(value, sort_keys=True), encoding="utf-8")
+        os.replace(temporary, sdk / "searchi-provenance.json")
+    finally:
+        temporary.unlink(missing_ok=True)
+
+
+def owned_path(directory, path):
+    """Resolve and reject escaped/reparse targets before directory moves."""
+    owner = directory.resolve()
+    target = path.resolve()
+    if target == owner or not target.is_relative_to(owner):
+        raise ValueError("Vulkan SDK path escapes owned toolchains directory")
+    return target
+
+
+def install_sdk(directory, sdk, installer):
+    # Qt's copy-only installer refuses an existing root. Use a fresh sibling,
+    # validate it fully, then swap; preserve previous/failed trees for recovery.
+    sdk = owned_path(directory, sdk)
+    staging = owned_path(directory, directory / f"vulkan-sdk-{VERSION}-staging-{uuid.uuid4().hex}")
+    backup = owned_path(directory, directory / f"vulkan-sdk-{VERSION}-backup-{uuid.uuid4().hex}")
+    if staging.exists() or backup.exists():
+        raise RuntimeError("Generated Vulkan staging or backup directory already exists")
+    environment = dict(os.environ, QT_OPENGL="software", SEARCHI_FORCE_CPU="1")
+    subprocess.run([str(installer), "--root", str(staging), "--accept-licenses", "--default-answer",
+        "--confirm-command", "install", "copy_only=1"], env=environment, check=True,
+        creationflags=subprocess.CREATE_NO_WINDOW)
+    write_sdk_provenance(staging)
+    if not sdk_verified(staging):
+        raise RuntimeError("Fresh Vulkan SDK failed provenance validation")
+    # Re-resolve immediately before mutation; no recursive removal is performed.
+    owned_path(directory, staging)
+    owned_path(directory, sdk)
+    owned_path(directory, backup)
+    previous = sdk.exists()
+    if previous:
+        os.replace(sdk, backup)
+    try:
+        os.replace(staging, sdk)
+    except OSError:
+        if previous and not sdk.exists():
+            owned_path(directory, backup)
+            owned_path(directory, sdk)
+            os.replace(backup, sdk)
+        raise
+
+
+def stage_loader(archive, loader):
+    if digest(archive) != LOADER_SHA:
+        raise ValueError("Vulkan runtime archive checksum mismatch")
+    prefix = f"VulkanRT-X64-{VERSION}-Components/"
+    members = []
+    with zipfile.ZipFile(archive) as package:
+        for source, name in [("x64/vulkan-1.dll", "vulkan-1.dll"),
+                             ("VulkanRT-License.txt", "VULKAN-LICENSE.txt")]:
+            member = package.getinfo(prefix + source)
+            if member.file_size > 16 * 1024 * 1024:
+                raise ValueError("Vulkan runtime member exceeds bound")
+            with package.open(member) as stream:
+                data = stream.read(16 * 1024 * 1024 + 1)
+            if len(data) != member.file_size or len(data) > 16 * 1024 * 1024:
+                raise ValueError("Vulkan runtime member exceeds bound or is truncated")
+            members.append((name, data))
+    loader.mkdir(exist_ok=True)
+    for name, data in members:
+        destination = loader / name
+        if destination.is_file() and digest(destination) == hashlib.sha256(data).hexdigest():
+            continue  # Never rewrite a verified DLL mapped by another process.
+        temporary = destination.with_suffix(destination.suffix + ".partial")
+        try:
+            temporary.write_bytes(data)
+            os.replace(temporary, destination)
+        finally:
+            temporary.unlink(missing_ok=True)
+
+
+def provision():
+    if os.name != "nt" or platform.machine().lower() not in {"amd64", "x86_64"}:
+        raise RuntimeError("Automatic Vulkan tooling provisioning is verified for Windows x64 only")
+    directory = ROOT / ".searchi/toolchains"
+    directory.mkdir(parents=True, exist_ok=True)
+    sdk = directory / f"vulkan-sdk-{VERSION}"
+    if not sdk_verified(sdk):
+        installer = directory / f"vulkansdk-windows-X64-{VERSION}.exe"
+        download(installer, installer.name, SDK_SHA, 400 * 1024 * 1024)
+        install_sdk(directory, sdk, installer)
+    archive = directory / f"VulkanRT-X64-{VERSION}-Components.zip"
+    download(archive, "vulkan-runtime-components.zip", LOADER_SHA, 50 * 1024 * 1024)
+    loader = directory / "vulkan-loader"
+    stage_loader(archive, loader)
+    return sdk, loader
+
+
+if __name__ == "__main__":
+    sdk, loader = provision()
+    print(f"Verified SDK: {sdk}\nApp-local loader: {loader}")

tools/embeddinggemma2/stage_runtime.py

@@ -42,17 +42,24 @@ def main():
     if args.bundle_model:
         manifest = json.loads(Path(__file__).with_name("model-manifest.json").read_text())
         artifacts = verify_bundle(ROOT, manifest)
+    loader = None
+    if os.name == "nt" and args.backend in {"auto", "vulkan"}:
+        from provision_vulkan import provision
+        _, loader = provision()
     destination = ROOT / "apps/desktop/src-tauri/resources"
     destination.mkdir(parents=True, exist_ok=True)
     shutil.copy2(source, destination / name)
     # Include the upstream runtime license with the statically linked helper.
     shutil.copy2(license_path, destination / "LLAMA-LICENSE.txt")
+    if loader:
+        for name in ["vulkan-1.dll", "VULKAN-LICENSE.txt"]:
+            shutil.copy2(loader / name, destination / name)
     if args.bundle_model:
         model_destination = destination / "embeddinggemma2"
         model_destination.mkdir(exist_ok=True)
         for artifact in artifacts:
             shutil.copy2(artifact, model_destination / artifact.name)
-    print(f"Staged native worker: {destination / name}")
+    print(f"Staged native worker: {destination / source.name}")
 
 
 if __name__ == "__main__":

tools/embeddinggemma2/test_provision_vulkan.py

@@ -0,0 +1,145 @@
+import hashlib
+import io
+from pathlib import Path
+import tempfile
+import subprocess
+import unittest
+import zipfile
+from unittest.mock import patch
+
+import provision_vulkan as provisioning
+from provision_vulkan import download, sdk_verified, write_sdk_provenance, stage_loader
+
+
+class DownloadTests(unittest.TestCase):
+    @staticmethod
+    def fake_sdk(sdk):
+        for name in ["Bin/glslc.exe", "Lib/vulkan-1.lib", "Include/vulkan/vulkan.h",
+                     "Include/vulkan/vulkan_core.h"]:
+            path = sdk / name
+            path.parent.mkdir(parents=True, exist_ok=True)
+            path.write_bytes(name.encode())
+
+    def test_fresh_install_preserves_previous_cache_and_uses_copy_only(self):
+        with tempfile.TemporaryDirectory() as directory:
+            root = Path(directory)
+            sdk = root / "sdk"
+            sdk.mkdir()
+            (sdk / "old-marker").write_bytes(b"previous tree")
+
+            def install(command, **options):
+                fresh = Path(command[command.index("--root") + 1])
+                self.assertFalse(fresh.exists())
+                self.assertIn("copy_only=1", command)
+                self.assertEqual(options["env"]["QT_OPENGL"], "software")
+                self.assertEqual(options["env"]["SEARCHI_FORCE_CPU"], "1")
+                self.fake_sdk(fresh)
+
+            with patch("provision_vulkan.subprocess.run", side_effect=install):
+                provisioning.install_sdk(root, sdk, root / "installer.exe")
+            self.assertTrue(sdk_verified(sdk))
+            backups = list(root.glob("*-backup-*"))
+            self.assertEqual(len(backups), 1)
+            self.assertEqual((backups[0] / "old-marker").read_bytes(), b"previous tree")
+
+    def test_failed_installer_and_failed_swap_preserve_previous_provenance(self):
+        for failure in ["installer", "swap"]:
+            with self.subTest(failure=failure), tempfile.TemporaryDirectory() as directory:
+                root = Path(directory)
+                sdk = root / "sdk"
+                self.fake_sdk(sdk)
+                write_sdk_provenance(sdk)
+                old_manifest = (sdk / "searchi-provenance.json").read_bytes()
+
+                def install(command, **options):
+                    if failure == "installer":
+                        raise subprocess.CalledProcessError(1, command)
+                    self.fake_sdk(Path(command[command.index("--root") + 1]))
+
+                real_replace = provisioning.os.replace
+
+                def replace(source, destination):
+                    if failure == "swap" and "-staging-" in Path(source).name and Path(destination) == sdk:
+                        raise PermissionError("injected swap failure")
+                    real_replace(source, destination)
+
+                with patch("provision_vulkan.subprocess.run", side_effect=install), \
+                     patch("provision_vulkan.os.replace", side_effect=replace):
+                    with self.assertRaises((OSError, subprocess.CalledProcessError)):
+                        provisioning.install_sdk(root, sdk, root / "installer.exe")
+                self.assertEqual((sdk / "searchi-provenance.json").read_bytes(), old_manifest)
+                self.assertTrue(sdk_verified(sdk))
+
+    def test_install_rejects_target_outside_owned_directory(self):
+        with tempfile.TemporaryDirectory() as directory:
+            root = Path(directory)
+            owned = root / "owned"
+            owned.mkdir()
+            with patch("provision_vulkan.subprocess.run", side_effect=AssertionError("installer ran")):
+                with self.assertRaisesRegex(ValueError, "escapes owned"):
+                    provisioning.install_sdk(owned, root / "outside", root / "installer.exe")
+
+    def test_sdk_requires_provenance_and_detects_header_corruption(self):
+        with tempfile.TemporaryDirectory() as directory:
+            sdk = Path(directory)
+            for name in ["Bin/glslc.exe", "Lib/vulkan-1.lib", "Include/vulkan/vulkan.h",
+                         "Include/vulkan/vulkan_core.h", "Include/vk_video/video.h"]:
+                path = sdk / name
+                path.parent.mkdir(parents=True, exist_ok=True)
+                path.write_bytes(name.encode())
+            self.assertFalse(sdk_verified(sdk))
+            write_sdk_provenance(sdk)
+            self.assertTrue(sdk_verified(sdk))
+            (sdk / "Include/vk_video/video.h").write_bytes(b"corrupt")
+            self.assertFalse(sdk_verified(sdk))
+
+    def test_verified_loader_is_not_replaced_and_bad_archive_preserves_it(self):
+        with tempfile.TemporaryDirectory() as directory:
+            root = Path(directory)
+            archive = root / "runtime.zip"
+            prefix = f"VulkanRT-X64-{provisioning.VERSION}-Components/"
+            with zipfile.ZipFile(archive, "w") as package:
+                package.writestr(prefix + "x64/vulkan-1.dll", b"verified loader")
+                package.writestr(prefix + "VulkanRT-License.txt", b"license")
+                package.writestr("../outside", b"ignored")
+            checksum = provisioning.digest(archive)
+            loader = root / "loader"
+            with patch.object(provisioning, "LOADER_SHA", checksum):
+                stage_loader(archive, loader)
+                with patch("provision_vulkan.os.replace", side_effect=AssertionError("rewrote loader")):
+                    stage_loader(archive, loader)
+                archive.write_bytes(b"corrupt")
+                with self.assertRaisesRegex(ValueError, "archive checksum"):
+                    stage_loader(archive, loader)
+            self.assertEqual((loader / "vulkan-1.dll").read_bytes(), b"verified loader")
+            self.assertFalse((root / "outside").exists())
+
+    def test_unsupported_architecture_fails_before_filesystem_or_network(self):
+        with patch("provision_vulkan.platform.machine", return_value="ARM64"), \
+             patch("provision_vulkan.Path.mkdir", side_effect=AssertionError("filesystem")), \
+             patch("provision_vulkan.urllib.request.urlopen", side_effect=AssertionError("network")):
+            with self.assertRaisesRegex(RuntimeError, "Windows x64 only"):
+                provisioning.provision()
+
+    def test_verified_cache_needs_no_network(self):
+        with tempfile.TemporaryDirectory() as directory:
+            path = Path(directory) / "sdk.exe"
+            path.write_bytes(b"verified SDK")
+            checksum = hashlib.sha256(path.read_bytes()).hexdigest()
+            with patch("provision_vulkan.urllib.request.urlopen", side_effect=AssertionError("unexpected network")):
+                download(path, "sdk.exe", checksum, 100)
+
+    def test_corrupt_or_oversized_download_preserves_previous_file(self):
+        for payload, limit, reason in [(b"wrong", 100, "checksum"), (b"too large", 2, "size ceiling")]:
+            with self.subTest(reason=reason), tempfile.TemporaryDirectory() as directory:
+                path = Path(directory) / "sdk.exe"
+                path.write_bytes(b"previous cached file")
+                with patch("provision_vulkan.urllib.request.urlopen", return_value=io.BytesIO(payload)):
+                    with self.assertRaisesRegex(ValueError, reason):
+                        download(path, "sdk.exe", hashlib.sha256(b"expected").hexdigest(), limit)
+                self.assertEqual(path.read_bytes(), b"previous cached file")
+                self.assertFalse(path.with_suffix(".exe.partial").exists())
+
+
+if __name__ == "__main__":
+    unittest.main()

tools/package_windows.py

@@ -33,14 +33,17 @@ def pe_machine(path):
 def package(root, executable, output):
     resources = root / "apps/desktop/src-tauri/resources"
     selected = [(executable, "searchi.exe"), (root / "LICENSE", "LICENSE.txt")]
-    for name in ["searchi-gemma-worker.exe", "LLAMA-LICENSE.txt", "media-runtime/manifest.json",
+    for name in ["searchi-gemma-worker.exe", "LLAMA-LICENSE.txt", "vulkan-1.dll", "VULKAN-LICENSE.txt", "media-runtime/manifest.json",
-                 "media-runtime/bin/ffmpeg.exe", "media-runtime/bin/ffprobe.exe"]:
+                 "media-runtime/bin/ffmpeg.exe", "media-runtime/bin/ffprobe.exe",
+                 "licenses/Inter-OFL.txt", "licenses/Fluent-MIT.txt", "media-runtime/licenses/LICENSE.txt"]:
         selected.append((resources / name, name))
     for directory in ["licenses", "media-runtime/licenses"]:
         notices = list((resources / directory).rglob("*.txt"))
         if not notices:
             raise ValueError(f"Required notices are missing: {directory}")
-        selected.extend((path, path.relative_to(resources).as_posix()) for path in notices)
+        selected_names = {name for _, name in selected}
+        selected.extend((path, path.relative_to(resources).as_posix()) for path in notices
+                        if path.relative_to(resources).as_posix() not in selected_names)
     machine = pe_machine(executable)
     architecture = {0x8664: "x86_64", 0xAA64: "aarch64"}.get(machine)
     if architecture is None:
@@ -50,7 +53,7 @@ def package(root, executable, output):
             raise ValueError(f"Required package file is missing: {name}")
         if path != executable and path != root / "LICENSE" and not path.resolve().is_relative_to(resources.resolve()):
             raise ValueError("Resource resolves outside the staging directory")
-        if name.endswith(".exe") and pe_machine(path) != machine:
+        if name.endswith((".exe", ".dll")) and pe_machine(path) != machine:
             raise ValueError(f"Executable architecture differs: {name}")
     records = []
     output.parent.mkdir(parents=True, exist_ok=True)
@@ -59,10 +62,17 @@ def package(root, executable, output):
     try:
         with zipfile.ZipFile(temporary_path, "w", zipfile.ZIP_DEFLATED, compresslevel=6) as archive:
             for path, name in selected:
-                with path.open("rb") as stream:
+                # Hash and count the same blocks written to the archive: a
-                    checksum = hashlib.file_digest(stream, "sha256").hexdigest()
+                # second source read or subsequent stat can describe different
-                archive.write(path, name)
+                # bytes when a staged file changes during release preparation.
-                records.append({"path": name, "bytes": path.stat().st_size, "sha256": checksum})
+                checksum = hashlib.sha256()
+                count = 0
+                with path.open("rb") as stream, archive.open(name, "w", force_zip64=True) as entry:
+                    while block := stream.read(1024 * 1024):
+                        entry.write(block)
+                        checksum.update(block)
+                        count += len(block)
+                records.append({"path": name, "bytes": count, "sha256": checksum.hexdigest()})
             archive.writestr("PACKAGE.json", json.dumps({"platform": "windows", "architecture": architecture,
                 "status": "unsigned development package; clean-machine verification pending", "files": records}, indent=2))
             archive.writestr("START-HERE.txt", "searchi — Find what matters. Locally.\n\n"

tools/test_package_windows.py

@@ -4,6 +4,7 @@ from pathlib import Path
 import struct
 import tempfile
 import unittest
+from unittest import mock
 import zipfile
 
 from package_windows import package
@@ -26,9 +27,9 @@ class PackageTests(unittest.TestCase):
         app = root / "build/app.exe"
         executable(app)
         (root / "LICENSE").write_text("application notice")
-        for name in ["searchi-gemma-worker.exe", "media-runtime/bin/ffmpeg.exe", "media-runtime/bin/ffprobe.exe"]:
+        for name in ["searchi-gemma-worker.exe", "vulkan-1.dll", "media-runtime/bin/ffmpeg.exe", "media-runtime/bin/ffprobe.exe"]:
             executable(resources / name)
-        for name in ["LLAMA-LICENSE.txt", "licenses/font.txt", "media-runtime/licenses/LICENSE.txt", "media-runtime/manifest.json"]:
+        for name in ["LLAMA-LICENSE.txt", "VULKAN-LICENSE.txt", "licenses/Inter-OFL.txt", "licenses/Fluent-MIT.txt", "media-runtime/licenses/LICENSE.txt", "media-runtime/manifest.json"]:
             path = resources / name
             path.parent.mkdir(parents=True, exist_ok=True)
             path.write_text("notice")
@@ -44,6 +45,8 @@ class PackageTests(unittest.TestCase):
                 self.assertIn("media-runtime/bin/ffprobe.exe", archive.namelist())
                 for record in json.loads(archive.read("PACKAGE.json"))["files"]:
                     self.assertEqual(hashlib.sha256(archive.read(record["path"])).hexdigest(), record["sha256"])
+                    self.assertEqual(len(archive.read(record["path"])), record["bytes"])
+                self.assertEqual(len(archive.namelist()), len(set(archive.namelist())))
 
     def test_mixed_architecture_preserves_previous_archive(self):
         with tempfile.TemporaryDirectory() as directory:
@@ -54,6 +57,62 @@ class PackageTests(unittest.TestCase):
                 package(root, app, output)
             self.assertEqual(output.read_bytes(), b"previous package")
 
+    def test_changed_source_records_exact_archived_bytes(self):
+        with tempfile.TemporaryDirectory() as directory:
+            root, _, app, output = self.fixture(directory)
+            original_open = zipfile.ZipFile.open
+
+            def mutate_source(archive, name, mode="r", *args, **kwargs):
+                if name == "searchi.exe" and mode == "w":
+                    # Change bytes after preflight and after the input stream
+                    # opens, at the point ZIP copying starts.
+                    app.write_bytes(app.read_bytes() + b"changed while packaging")
+                return original_open(archive, name, mode, *args, **kwargs)
+
+            with mock.patch.object(zipfile.ZipFile, "open", mutate_source):
+                package(root, app, output)
+            with zipfile.ZipFile(output) as archive:
+                content = archive.read("searchi.exe")
+                record = json.loads(archive.read("PACKAGE.json"))["files"][0]
+                self.assertIn(b"changed while packaging", content)
+                self.assertEqual(record["bytes"], len(content))
+                self.assertEqual(record["sha256"], hashlib.sha256(content).hexdigest())
+
+    def test_mid_write_failure_preserves_previous_archive_and_cleans_temporary(self):
+        with tempfile.TemporaryDirectory() as directory:
+            root, _, app, output = self.fixture(directory)
+            output.write_bytes(b"previous package")
+            original_open = zipfile.ZipFile.open
+
+            def fail_second_entry(archive, name, mode="r", *args, **kwargs):
+                if name == "LICENSE.txt" and mode == "w":
+                    raise OSError("simulated storage failure")
+                return original_open(archive, name, mode, *args, **kwargs)
+
+            with mock.patch.object(zipfile.ZipFile, "open", fail_second_entry):
+                with self.assertRaisesRegex(OSError, "storage failure"):
+                    package(root, app, output)
+            self.assertEqual(output.read_bytes(), b"previous package")
+            self.assertEqual(list(output.parent.glob("*.partial")), [])
+
+    def test_missing_named_notice_preserves_previous_archive(self):
+        with tempfile.TemporaryDirectory() as directory:
+            root, resources, app, output = self.fixture(directory)
+            output.write_bytes(b"previous package")
+            (resources / "licenses/Inter-OFL.txt").unlink()
+            with self.assertRaisesRegex(ValueError, "Inter-OFL"):
+                package(root, app, output)
+            self.assertEqual(output.read_bytes(), b"previous package")
+
+    def test_mixed_loader_architecture_preserves_previous_archive(self):
+        with tempfile.TemporaryDirectory() as directory:
+            root, resources, app, output = self.fixture(directory)
+            output.write_bytes(b"previous package")
+            executable(resources / "vulkan-1.dll", 0xAA64)
+            with self.assertRaisesRegex(ValueError, "architecture differs: vulkan-1.dll"):
+                package(root, app, output)
+            self.assertEqual(output.read_bytes(), b"previous package")
+
 
 if __name__ == "__main__":
     unittest.main()