feat(versions): link at ingest, hide in listings, version endpoints

XMP (PNG iTXt DerivedFrom, native chunk reader) then file-name convention
links at ingest; unlinked name candidates are retried each tick. Versions
are hidden from /photos (SQL for the recursive listing, hidden-row set for
the walk and tag branches), /memories, reels, /photos/exif, the GPS summary,
unified search and the media gauges while their original is reachable in the
view; include_versions=true lists them. /photos gains the parallel arrays
photo_display_paths / photo_version_counts, memories / search hits /
/photos/exif rows gain display_path / version_count, all skipped when empty.
GET /image/versions and PUT /image/versions/display (library optional).
Tags and favorites on a version path bind to the original; faces, CLIP and
duplicate grouping skip version hashes; insight generation redirects to the
original. Orphan GC and the back-ref refresh cover the new tables.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/ai/handlers.rs

@@ -430,7 +430,17 @@ pub async fn generate_insight_handler(
         &mut request.persona_id,
     );
 
+    // Insights describe the original: asking for one on a photo version
+    // (#191) runs against the original it belongs to.
     let normalized_path = normalize_path(&request.file_path);
+    let normalized_path = app_state
+        .version_dao
+        .lock()
+        .expect("Unable to lock VersionDao")
+        .original_path_of(&normalized_path)
+        .ok()
+        .flatten()
+        .unwrap_or(normalized_path);
     let library = app_state.primary_library();
     let gen_type = InsightGenerationType::Standard;
 
@@ -748,7 +758,17 @@ pub async fn generate_agentic_insight_handler(
         &mut request.persona_id,
     );
 
+    // Insights describe the original: asking for one on a photo version
+    // (#191) runs against the original it belongs to.
     let normalized_path = normalize_path(&request.file_path);
+    let normalized_path = app_state
+        .version_dao
+        .lock()
+        .expect("Unable to lock VersionDao")
+        .original_path_of(&normalized_path)
+        .ok()
+        .flatten()
+        .unwrap_or(normalized_path);
     let library = app_state.primary_library();
     let gen_type = InsightGenerationType::Agentic;