feat: integrate Google semantic search and branded desktop launcher

docs/ROADMAP.md

@@ -2,6 +2,21 @@
 
 Status: implementation started; no production release yet. Windows VM tests use CPU only.
 
+## Required product scope (user clarification)
+
+- Desktop UI is primary; semantic setup/indexing/search must require no terminal.
+- Google EmbeddingGemma 2 is the required production model, matching DigUp.
+- Local document, image, audio and video search are required product milestones.
+- A separate CLI-only build supports headless Linux without desktop dependencies.
+- Production automatically uses available hardware acceleration with CPU fallback;
+  this Windows VM is tested in forced-CPU mode only.
+- Installer ships the native worker. First launch automatically downloads/verifies
+  missing model files and manages indexing in the UI; no terminal setup is required.
+- Earlier MiniLM proof is an experiment and does not satisfy the model requirement.
+- First interaction must be responsive: prepare indexes and a real Google query
+  in the background, retain ready sessions, and show immediate keyword results.
+  Model download and initialization must have honest progress and retry states.
+
 ## 1. Search foundation
 - [x] Rust workspace, reusable engine, CLI, versioned SQLite storage.
 - [ ] Filename/path and ranked full-text retrieval with strict filters.
@@ -30,6 +45,9 @@ Status: implementation started; no production release yet. Windows VM tests use
 - [ ] Formatting, lint, tests and security/dependency review.
 - [ ] CPU benchmarks: filename p95 <50 ms/1M records; text <150 ms/100K documents; semantic <500 ms on declared hardware.
 - [ ] Measure cold start, indexing throughput, RAM, disk and idle CPU.
+- [ ] Record the very first foreground query and distinct unseen queries after
+  production background preparation; report initialization time separately.
+  Warm p95 alone does not satisfy the first-use requirement.
 - [ ] Test migrations, interrupted work, invalid documents, inaccessible/offline roots and cloud placeholders.
 - [ ] Automated native build matrix and documented supported cross-compilation paths.
 - [ ] Execute Linux/macOS platform tests; create Windows/macOS/Linux installers.