Filter exact music identities before lexical and semantic candidate limits

crates/searchi-core/README.md

@@ -136,3 +136,15 @@ opens. The measured Windows synthetic fixture grew from about 295 MiB to 605 MiB
 - OCR, media extraction, and real model inference belong to subsequent modules.
 - Linux/macOS measurements, realistic mixed-document corpora, cold startup,
   memory budgets, and indexing performance remain unverified.
+
+### Exact music identities
+
+`SearchOptions.media_artist` and `media_title` constrain every retrieval lane to
+complete genuine probe fields, with Unicode simple lowercase and outer whitespace
+normalization. Both fields combine with AND; substring inference and full Unicode
+case folding are not claimed. Each request field accepts 1–1024 UTF-8 bytes.
+An empty query with either constraint returns bounded filename/path-ordered matches.
+Missing tags and legacy flattened-only records are ineligible, rather than admitting
+semantic neighbours. A normal media probe refresh populates the structured keys.
+Oversized genuine fields remain keyword-searchable but receive no truncated exact
+identity key. Guarded publication and same-stat event hints preserve invalidation.

crates/searchi-core/src/lib.rs

@@ -17,14 +17,14 @@ use rusqlite::{params, params_from_iter, types::Value, Connection, OptionalExten
 use serde::Serialize;
 use std::{
     cell::RefCell,
-    collections::{BTreeSet, HashMap},
+    collections::{BTreeMap, BTreeSet, HashMap},
     fs,
     path::{Path, PathBuf},
     sync::atomic::{AtomicBool, Ordering},
 };
 use walkdir::WalkDir;
 
-const SCHEMA_VERSION: i64 = 13;
+const SCHEMA_VERSION: i64 = 14;
 const MAX_RESULTS: usize = 1000;
 
 type PreviousExtraction = (i64, i64, String, Option<String>, Option<String>);
@@ -70,6 +70,19 @@ pub struct SearchOptions {
     pub modified_before_unix_ms: Option<i64>,
     pub min_duration_ms: Option<u32>,
     pub max_duration_ms: Option<u32>,
+    /// Exact complete artist tag, Unicode lowercase comparison. Never inferred from query text.
+    pub media_artist: Option<String>,
+    /// Exact complete title tag; missing structured tags are ineligible.
+    pub media_title: Option<String>,
+}
+
+/// Shared bounded normalization for exact metadata constraints and genuine probe values.
+pub fn normalize_media_field(value: &str) -> Result<String> {
+    let value = value.trim();
+    if value.is_empty() || value.len() > 1024 {
+        bail!("Exact media field must contain 1..=1024 UTF-8 bytes");
+    }
+    Ok(value.to_lowercase())
 }
 
 #[derive(Debug, Serialize)]
@@ -282,7 +295,19 @@ impl SearchIndex {
                     [],
                 )?;
             }
-            initialization.execute_batch("PRAGMA user_version=13;")?;
+            for field in ["artist_key", "title_key"] {
+                let exists: bool = initialization.query_row(
+                    "SELECT EXISTS(SELECT 1 FROM pragma_table_info('media_metadata') WHERE name=?1)",
+                    [field], |row| row.get(0),
+                )?;
+                if !exists {
+                    initialization.execute(
+                        &format!("ALTER TABLE media_metadata ADD COLUMN {field} TEXT"),
+                        [],
+                    )?;
+                }
+            }
+            initialization.execute_batch("PRAGMA user_version=14;")?;
             initialization.commit()?;
         }
         Ok(Self {
@@ -356,6 +381,78 @@ impl SearchIndex {
         size: u64,
         mtime_ns: i64,
         expected_revision: i64,
+    ) -> Result<()> {
+        self.write_media_metadata(
+            path,
+            tags,
+            None,
+            None,
+            duration_ms,
+            size,
+            mtime_ns,
+            expected_revision,
+        )
+    }
+
+    /// Preserve structured fields directly from a genuine probe, never from flattened text.
+    /// Empty/oversized fields retain legacy keyword tags but have no exact identity key.
+    #[allow(clippy::too_many_arguments)]
+    pub fn set_structured_media_metadata_at_revision(
+        &mut self,
+        path: &str,
+        tags: &BTreeMap<String, String>,
+        duration_ms: u32,
+        size: u64,
+        mtime_ns: i64,
+        expected_revision: i64,
+    ) -> Result<()> {
+        let field = |name: &str| -> Result<Option<String>> {
+            tags.get(name)
+                .filter(|value| !value.trim().is_empty() && value.trim().len() <= 1024)
+                .map(|value| normalize_media_field(value))
+                .transpose()
+        };
+        let mut total = 0usize;
+        for (key, value) in tags {
+            total = total
+                .checked_add(key.len())
+                .and_then(|n| n.checked_add(value.len()))
+                .and_then(|n| n.checked_add(3))
+                .context("Media tags size overflow")?;
+            if total > 32768 {
+                bail!("Media tags exceed 32 KiB bound");
+            }
+        }
+        let artist = field("artist")?;
+        let title = field("title")?;
+        let flattened = tags
+            .iter()
+            .map(|(key, value)| format!("{key}: {value}"))
+            .collect::<Vec<_>>()
+            .join("\n");
+        self.write_media_metadata(
+            path,
+            &flattened,
+            artist.as_deref(),
+            title.as_deref(),
+            duration_ms,
+            size,
+            mtime_ns,
+            expected_revision,
+        )
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    fn write_media_metadata(
+        &mut self,
+        path: &str,
+        tags: &str,
+        artist: Option<&str>,
+        title: Option<&str>,
+        duration_ms: u32,
+        size: u64,
+        mtime_ns: i64,
+        expected_revision: i64,
     ) -> Result<()> {
         if tags.len() > 32768 {
             bail!("Media tags exceed 32 KiB bound");
@@ -369,7 +466,7 @@ impl SearchIndex {
             )
             .optional()?;
         let id = id.context("Media metadata file changed since indexing")?;
-        tx.execute("INSERT INTO media_metadata(path,file_id,tags,duration_ms) VALUES(?1,?2,?3,?4) ON CONFLICT(path) DO UPDATE SET tags=excluded.tags,duration_ms=excluded.duration_ms",params![path,id,tags,duration_ms])?;
+        tx.execute("INSERT INTO media_metadata(path,file_id,tags,duration_ms,artist_key,title_key) VALUES(?1,?2,?3,?4,?5,?6) ON CONFLICT(path) DO UPDATE SET tags=excluded.tags,duration_ms=excluded.duration_ms,artist_key=excluded.artist_key,title_key=excluded.title_key",params![path,id,tags,duration_ms,artist,title])?;
         tx.commit()?;
         Ok(())
     }
@@ -916,8 +1013,19 @@ impl SearchIndex {
             .map(i64::try_from)
             .transpose()
             .context("maximum size exceeds supported range")?;
+        let artist = options
+            .media_artist
+            .as_deref()
+            .map(normalize_media_field)
+            .transpose()?;
+        let title = options
+            .media_title
+            .as_deref()
+            .map(normalize_media_field)
+            .transpose()?;
+        let metadata_only = query.trim().is_empty() && (artist.is_some() || title.is_some());
         let query = query.trim();
-        if query.is_empty() || limit == 0 {
+        if (query.is_empty() && !metadata_only) || limit == 0 {
             return Ok(Vec::new());
         }
         if query.len() > 4096 {
@@ -937,7 +1045,9 @@ impl SearchIndex {
             AND (?5 IS NULL OR f.size>=?5) AND (?6 IS NULL OR f.size<=?6)
             AND (?7 IS NULL OR f.mtime/1000000>=?7) AND (?8 IS NULL OR f.mtime/1000000<=?8)
             AND (?10 IS NULL OR EXISTS(SELECT 1 FROM media_metadata m WHERE m.file_id=f.id AND m.duration_ms>=?10))
-            AND (?11 IS NULL OR EXISTS(SELECT 1 FROM media_metadata m WHERE m.file_id=f.id AND m.duration_ms<=?11))");
+            AND (?11 IS NULL OR EXISTS(SELECT 1 FROM media_metadata m WHERE m.file_id=f.id AND m.duration_ms<=?11))
+            AND (?12 IS NULL OR EXISTS(SELECT 1 FROM media_metadata m WHERE m.file_id=f.id AND m.artist_key=?12))
+            AND (?13 IS NULL OR EXISTS(SELECT 1 FROM media_metadata m WHERE m.file_id=f.id AND m.title_key=?13))");
         if options.code_only {
             filters.push_str(" AND ");
             filters.push_str(code_file_predicate());
@@ -957,7 +1067,9 @@ impl SearchIndex {
         let has_filters = filter_values.iter().any(|value| *value != Value::Null)
             || options.code_only
             || options.min_duration_ms.is_some()
-            || options.max_duration_ms.is_some();
+            || options.max_duration_ms.is_some()
+            || artist.is_some()
+            || title.is_some();
         let mut results = Vec::new();
         let mut selected = Vec::<i64>::new();
         // Each lane filters its entire candidate set before LIMIT. There is no
@@ -1084,6 +1196,15 @@ impl SearchIndex {
             fts.clone(),
             "rank,f.id",
         ));
+        if metadata_only {
+            lanes = vec![(
+                "metadata_filter",
+                "files f".into(),
+                "(?1 IS NOT NULL AND ?2 IS NOT NULL)".into(),
+                String::new(),
+                "f.filename,f.path",
+            )];
+        }
         trace.end(planning, Default::default());
         for (kind, from, condition, expression, ordering) in lanes {
             if results.len() == limit {
@@ -1161,6 +1282,10 @@ impl SearchIndex {
                         .map_or(Value::Null, |v| Value::Integer(i64::from(v))),
                 );
             }
+            if sql.contains("?12") {
+                values.push(artist.clone().map_or(Value::Null, Value::Text));
+                values.push(title.clone().map_or(Value::Null, Value::Text));
+            }
             let sql_span = trace.begin("lexical.filtered_sql", lane);
             trace.counter(sql_span, "filters_active", u64::from(has_filters));
             let mut statement = self.connection.prepare(&sql)?;
@@ -1435,6 +1560,149 @@ fn validate_normalized_absolute(path: &Path) -> Result<()> {
 
 #[cfg(test)]
 mod tests {
+    #[test]
+    fn legacy_metadata_migration_preserves_keyword_search_without_inventing_fields(
+    ) -> anyhow::Result<()> {
+        use super::*;
+        let dir = tempfile::tempdir()?;
+        let root = dir.path().join("media");
+        fs::create_dir(&root)?;
+        let file = root.join("track.ogg");
+        fs::write(&file, b"legacy tag fixture")?;
+        let db = dir.path().join("index.db");
+        let mut index = SearchIndex::open(&db)?;
+        index.index_folder(&root)?;
+        let file = file.canonicalize()?;
+        let identity = searchi_media::MediaIdentity::read(&file, 1024)?;
+        index.set_media_metadata(
+            &file.to_string_lossy(),
+            "artist: Björk",
+            1000,
+            identity.bytes,
+            identity.modified_ns,
+        )?;
+        drop(index);
+        let connection = Connection::open(&db)?;
+        connection.execute_batch("ALTER TABLE media_metadata DROP COLUMN artist_key; ALTER TABLE media_metadata DROP COLUMN title_key; PRAGMA user_version=13;")?;
+        drop(connection);
+        let mut index = SearchIndex::open(&db)?;
+        assert_eq!(index.search("Björk", 1)?.len(), 1);
+        let options = SearchOptions {
+            media_artist: Some("Björk".into()),
+            ..Default::default()
+        };
+        assert!(index.search_with_options("", 1, &options)?.is_empty());
+        let revision = index.media_change_revision(
+            &file.to_string_lossy(),
+            identity.bytes,
+            identity.modified_ns,
+        )?;
+        let tags = BTreeMap::from([
+            ("artist".into(), "Björk".into()),
+            ("title".into(), "x".repeat(1025)),
+        ]);
+        index.set_structured_media_metadata_at_revision(
+            &file.to_string_lossy(),
+            &tags,
+            1000,
+            identity.bytes,
+            identity.modified_ns,
+            revision,
+        )?;
+        assert_eq!(index.search_with_options("", 1, &options)?.len(), 1);
+        assert_eq!(index.search("x".repeat(1025).as_str(), 1)?.len(), 1);
+        let too_short = SearchOptions {
+            media_title: Some("x".repeat(1024)),
+            ..Default::default()
+        };
+        assert!(index.search_with_options("", 1, &too_short)?.is_empty());
+        drop(index);
+        let index = SearchIndex::open(&db)?;
+        assert_eq!(index.search_with_options("", 1, &options)?.len(), 1);
+        Ok(())
+    }
+
+    #[test]
+    fn exact_structured_media_filters_preserve_fields_and_hint_invalidation() -> anyhow::Result<()>
+    {
+        use super::*;
+        let dir = tempfile::tempdir()?;
+        let path = dir.path().join("track.ogg");
+        fs::write(&path, b"tag storage fixture")?;
+        let mut index = SearchIndex::open(":memory:")?;
+        index.index_folder(dir.path())?;
+        let identity = searchi_media::MediaIdentity::read(&path, 1024)?;
+        let canonical = path.canonicalize()?;
+        let path_string = canonical.to_string_lossy();
+        let revision =
+            index.media_change_revision(&path_string, identity.bytes, identity.modified_ns)?;
+        let tags = BTreeMap::from([
+            ("artist".into(), "Björk".into()),
+            ("title".into(), "Jóga".into()),
+            ("comment".into(), "artist: Absent Artist".into()),
+        ]);
+        index.set_structured_media_metadata_at_revision(
+            &path_string,
+            &tags,
+            1000,
+            identity.bytes,
+            identity.modified_ns,
+            revision,
+        )?;
+        let mut options = SearchOptions {
+            media_artist: Some("  BJÖRK ".into()),
+            ..Default::default()
+        };
+        assert_eq!(index.search_with_options("", 1, &options)?.len(), 1);
+        assert_eq!(index.search_with_options("track", 1, &options)?.len(), 1);
+        options.media_title = Some("JÓGA".into());
+        assert_eq!(index.search_with_options("", 1, &options)?.len(), 1);
+        options.media_artist = Some("Absent Artist".into());
+        assert!(index.search_with_options("", 1, &options)?.is_empty());
+        options.media_artist = Some("Björ".into());
+        assert!(index.search_with_options("track", 1, &options)?.is_empty());
+        options.media_artist = Some("  ".into());
+        assert!(index.search_with_options("", 1, &options).is_err());
+        options.media_artist = Some("Björk".into());
+        index.index_paths_cancellable(
+            dir.path(),
+            std::slice::from_ref(&canonical),
+            &IndexOptions::default(),
+            &AtomicBool::new(false),
+        )?;
+        assert!(index.search_with_options("", 1, &options)?.is_empty());
+        assert!(index
+            .set_structured_media_metadata_at_revision(
+                &path_string,
+                &tags,
+                1000,
+                identity.bytes,
+                identity.modified_ns,
+                revision
+            )
+            .is_err());
+        let revision =
+            index.media_change_revision(&path_string, identity.bytes, identity.modified_ns)?;
+        index.set_structured_media_metadata_at_revision(
+            &path_string,
+            &tags,
+            1000,
+            identity.bytes,
+            identity.modified_ns,
+            revision,
+        )?;
+        assert_eq!(index.search_with_options("", 1, &options)?.len(), 1);
+        index.set_media_metadata(
+            &path_string,
+            "artist: Björk",
+            1000,
+            identity.bytes,
+            identity.modified_ns,
+        )?;
+        assert!(index.search_with_options("", 1, &options)?.is_empty());
+        assert_eq!(index.search("Björk", 1)?.len(), 1);
+        Ok(())
+    }
     #[test]
     fn measured_search_preserves_results_and_contains_private_free_nested_spans(
     ) -> anyhow::Result<()> {

crates/searchi-core/tests/targeted_reconciliation.rs

@@ -447,7 +447,7 @@ fn schema_twelve_migrates_change_revision_without_reextracting_records() -> Resu
     let connection = rusqlite::Connection::open(&db)?;
     assert_eq!(
         connection.query_row("PRAGMA user_version", [], |row| row.get::<_, i64>(0))?,
-        13
+        14
     );
     assert_eq!(
         connection.query_row("SELECT change_revision FROM files", [], |row| row

crates/searchi-service/README.md

@@ -41,3 +41,9 @@ Audio timestamps represent segment starts, not exact word locations. Smaller
 windows alone have not demonstrated accurate spoken navigation. No-answer
 calibration, music discrimination, exact spoken positions, process isolation,
 unchanged-vector reuse and production platform checks remain release gates.
+
+Exact artist/title constraints use the core's normalized structured probe keys
+before ANN limits and in the eligibility cache key. Metadata-only writes advance
+the corpus revision and dirty path so warmed readers cannot retain old eligibility.
+Empty metadata-only hybrid requests use core results without model inference.
+These explicit constraints do not establish abstention for free-form topic queries.

crates/searchi-service/src/lib.rs

@@ -513,7 +513,7 @@ impl HybridSearch {
             .lexical
             .search_with_options_traced(query, candidates, options, trace, parent)?;
         if query.trim().is_empty() || limit == 0 {
-            return Ok(Vec::new());
+            return Ok(lexical.into_iter().take(limit.min(1000)).collect());
         }
         trace.timed("hybrid.identifier_priority", parent, |_, _| {
             promote_identifiers(query.trim(), &mut lexical)
@@ -776,6 +776,24 @@ mod tests {
         let directory = tempfile::tempdir()?;
         let db = directory.path().join("index.db");
         let mut service = HybridSearch::with_provider(&db, Box::new(FailingProvider))?;
+        // The failure-only provider proves metadata-only searches never require inference.
+        let metadata = service.search_measured(
+            "",
+            5,
+            &SearchOptions {
+                media_artist: Some("Absent Artist".into()),
+                ..Default::default()
+            },
+            true,
+        )?;
+        assert!(metadata.results.is_empty());
+        assert!(!metadata
+            .metrics
+            .trace
+            .unwrap()
+            .iter()
+            .any(|span| span.name == "semantic.query_embedding"));
+
         let mut trace = TraceCollector::new(MetricsMode::Debug);
         assert!(service
             .search_traced(

crates/searchi-service/src/media.rs

@@ -190,15 +190,9 @@ impl HybridSearch {
         metadata: &MediaProbe,
         change_revision: i64,
     ) -> Result<()> {
-        let tags = metadata
+        self.lexical.set_structured_media_metadata_at_revision(
-            .tags
-            .iter()
-            .map(|(k, v)| format!("{k}: {v}"))
-            .collect::<Vec<_>>()
-            .join("\n");
-        self.lexical.set_media_metadata_at_revision(
             &path.to_string_lossy(),
-            &tags,
+            &metadata.tags,
             metadata.duration_ms,
             identity.bytes,
             identity.modified_ns,

crates/searchi-service/src/store.rs

@@ -31,6 +31,8 @@ struct FilterKey {
     max_duration: Option<u32>,
     source_type: Option<String>,
     code_only: bool,
+    media_artist: Option<String>,
+    media_title: Option<String>,
 }
 
 struct EligibilityCache {
@@ -184,6 +186,17 @@ impl Store {
             }
         }
         initialization.execute_batch("CREATE TABLE IF NOT EXISTS semantic_media_errors(generation INTEGER NOT NULL REFERENCES semantic_generations(id) ON DELETE CASCADE,path TEXT NOT NULL,message TEXT NOT NULL,PRIMARY KEY(generation,path))")?;
+        // Metadata-only writes change strict eligibility even when file bytes do not change.
+        for (name, event, row) in [
+            ("insert", "INSERT", "new"),
+            ("update", "UPDATE", "new"),
+            ("delete", "DELETE", "old"),
+        ] {
+            initialization.execute_batch(&format!("CREATE TRIGGER IF NOT EXISTS semantic_media_metadata_{name} AFTER {event} ON media_metadata BEGIN
+                UPDATE semantic_meta SET corpus_revision=corpus_revision+1 WHERE singleton=1;
+                INSERT INTO semantic_dirty_paths(path,revision) VALUES({row}.path,(SELECT corpus_revision FROM semantic_meta WHERE singleton=1))
+                ON CONFLICT(path) DO UPDATE SET revision=excluded.revision; END;"))?;
+        }
         incremental::migrate(&initialization)?;
         initialization.commit()?;
         let canonical = db.canonicalize()?;
@@ -644,6 +657,16 @@ impl Store {
             max_duration: options.max_duration_ms,
             source_type: source_type.map(str::to_owned),
             code_only: options.code_only,
+            media_artist: options
+                .media_artist
+                .as_deref()
+                .map(searchi_core::normalize_media_field)
+                .transpose()?,
+            media_title: options
+                .media_title
+                .as_deref()
+                .map(searchi_core::normalize_media_field)
+                .transpose()?,
         };
         trace.end(filter_span, Default::default());
         let eligibility_span = trace.begin("semantic.eligibility", parent);
@@ -883,6 +906,8 @@ impl Store {
             AND (?3 IS NULL OR f.extension=?3)
             AND (?4 IS NULL OR f.size>=?4) AND (?5 IS NULL OR f.size<=?5)
             AND (?6 IS NULL OR f.mtime/1000000>=?6) AND (?7 IS NULL OR f.mtime/1000000<=?7)
+            AND (?9 IS NULL OR EXISTS(SELECT 1 FROM media_metadata m WHERE m.path=f.path AND m.artist_key=?9))
+            AND (?10 IS NULL OR EXISTS(SELECT 1 FROM media_metadata m WHERE m.path=f.path AND m.title_key=?10))
             ORDER BY c.passage_id,c.ordinal LIMIT ?8")?;
         // Fetch one extra to detect the baseline cap instead of silently hiding
         // candidates. Metadata filtering precedes this cap and all top-k limits.
@@ -894,7 +919,17 @@ impl Store {
             max_size,
             options.modified_after_unix_ms,
             options.modified_before_unix_ms,
-            MAX_SCAN_CHUNKS as i64 + 1
+            MAX_SCAN_CHUNKS as i64 + 1,
+            options
+                .media_artist
+                .as_deref()
+                .map(searchi_core::normalize_media_field)
+                .transpose()?,
+            options
+                .media_title
+                .as_deref()
+                .map(searchi_core::normalize_media_field)
+                .transpose()?
         ])?;
         let mut hashes = HashMap::<i64, String>::new();
         let mut best = HashMap::<String, SearchResult>::new();
@@ -1008,6 +1043,8 @@ fn collect_eligibility(
         AND (?6 IS NULL OR f.mtime/1000000>=?6) AND (?7 IS NULL OR f.mtime/1000000<=?7)
         AND (?10 IS NULL OR EXISTS(SELECT 1 FROM media_metadata m WHERE m.path=f.path AND m.duration_ms>=?10))
         AND (?11 IS NULL OR EXISTS(SELECT 1 FROM media_metadata m WHERE m.path=f.path AND m.duration_ms<=?11))
+        AND (?13 IS NULL OR EXISTS(SELECT 1 FROM media_metadata m WHERE m.path=f.path AND m.artist_key=?13))
+        AND (?14 IS NULL OR EXISTS(SELECT 1 FROM media_metadata m WHERE m.path=f.path AND m.title_key=?14))
         AND (?12 IS NULL OR c.source_type=?12)
         AND (?9 IS NULL OR c.path=?9) {code} ORDER BY c.passage_id,c.ordinal LIMIT ?8"))?;
     let mut rows = statement.query(params![
@@ -1022,7 +1059,9 @@ fn collect_eligibility(
         path,
         filter.min_duration,
         filter.max_duration,
-        filter.source_type
+        filter.source_type,
+        filter.media_artist,
+        filter.media_title
     ])?;
     let mut hashes = HashMap::<i64, String>::new();
     let mut keys = HashSet::new();
@@ -1293,6 +1332,108 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn exact_metadata_filters_apply_before_ann_and_invalidate_warmed_eligibility() -> Result<()> {
+        let dir = tempfile::tempdir()?;
+        let root = dir.path().join("media");
+        std::fs::create_dir(&root)?;
+        std::fs::write(root.join("first.ogg"), b"metadata ANN eligibility fixture")?;
+        std::fs::write(root.join("other.ogg"), b"metadata distractor fixture")?;
+        let db = dir.path().join("index.db");
+        let mut lexical = SearchIndex::open(&db)?;
+        lexical.index_folder(&root)?;
+        let mut store = Store::open(&db, DIMENSIONS)?;
+        let mut files = store.media_batch(0)?;
+        files.sort_by(|a, b| a.1.cmp(&b.1));
+        let (other_id, other_path, _, _) = files.pop().context("distractor fixture")?;
+        let other_identity = searchi_media::MediaIdentity::read(Path::new(&other_path), 1024)?;
+        let (id, path, _, _) = files.remove(0);
+        let identity = searchi_media::MediaIdentity::read(Path::new(&path), 1024)?;
+        let revision =
+            lexical.media_change_revision(&path, identity.bytes, identity.modified_ns)?;
+        let mut tags = std::collections::BTreeMap::from([
+            ("artist".into(), "Björk".into()),
+            ("title".into(), "Jóga".into()),
+        ]);
+        lexical.set_structured_media_metadata_at_revision(
+            &path,
+            &tags,
+            1000,
+            identity.bytes,
+            identity.modified_ns,
+            revision,
+        )?;
+        // Deterministic geometry tests storage/filter behavior, not model quality.
+        let mut vector = vec![0.; DIMENSIONS];
+        vector[0] = 1.;
+        let generation = store.begin("metadata-filter-proof")?;
+        let mut weaker = vector.clone();
+        weaker[0] = 0.8;
+        weaker[1] = 0.6;
+        store.insert_media(generation, id, 0, &identity, "audio", 0, &weaker)?;
+        store.insert_media(
+            generation,
+            other_id,
+            0,
+            &other_identity,
+            "audio",
+            0,
+            &vector,
+        )?;
+        store.activate(generation)?;
+        let mut options = SearchOptions {
+            media_artist: Some("BJÖRK".into()),
+            media_title: Some("JÓGA".into()),
+            ..Default::default()
+        };
+        assert_eq!(
+            store
+                .search(&vector, "metadata-filter-proof", 1, &options)?
+                .len(),
+            1
+        );
+        options.media_artist = Some("Absent".into());
+        assert!(store
+            .search(&vector, "metadata-filter-proof", 1, &options)?
+            .is_empty());
+        options.media_artist = Some("BJÖRK".into());
+        assert_eq!(
+            store
+                .search(&vector, "metadata-filter-proof", 1, &options)?
+                .len(),
+            1
+        );
+        tags.insert("artist".into(), "Replacement".into());
+        lexical.set_structured_media_metadata_at_revision(
+            &path,
+            &tags,
+            1000,
+            identity.bytes,
+            identity.modified_ns,
+            revision,
+        )?;
+        assert!(store
+            .search(&vector, "metadata-filter-proof", 1, &options)?
+            .is_empty());
+        options.media_artist = Some("Replacement".into());
+        assert_eq!(
+            store
+                .search(&vector, "metadata-filter-proof", 1, &options)?
+                .len(),
+            1
+        );
+        lexical.index_paths_cancellable(
+            &root,
+            &[std::path::PathBuf::from(&path)],
+            &searchi_core::IndexOptions::default(),
+            &std::sync::atomic::AtomicBool::new(false),
+        )?;
+        assert!(store
+            .search(&vector, "metadata-filter-proof", 1, &options)?
+            .is_empty());
+        Ok(())
+    }
+
     #[test]
     fn media_origins_persist_filters_and_changes_remove_stale_candidates() -> Result<()> {
         let directory = tempfile::tempdir()?;