feat(worktree): query plumbing surfaces merged rows under parent project

ObservationCompiler.queryObservationsMulti and querySummariesMulti
WHERE clause extended with OR merged_into_project IN (...), so a
parent-project read pulls in rows originally written under any
child worktree's composite name once merged.

SearchManager wraps the Chroma project filter in \$or so semantic
search behaves identically. ChromaSync baseMetadata now carries
merged_into_project on new embeddings; existing rows are patched
retroactively by the adoption engine.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/services/worker/SearchManager.ts

@@ -170,8 +170,16 @@ export class SearchManager {
       // Include project in the Chroma where clause to scope vector search.
       // Without this, larger projects dominate the top-N results and smaller
       // projects get crowded out before the post-hoc SQLite filter.
+      // Match both native-provenance rows (project) and adopted merged-worktree
+      // rows (merged_into_project) so a parent-project query surfaces its
+      // merged children's observations too.
       if (options.project) {
-        const projectFilter = { project: options.project };
+        const projectFilter = {
+          $or: [
+            { project: options.project },
+            { merged_into_project: options.project }
+          ]
+        };
         whereFilter = whereFilter
           ? { $and: [whereFilter, projectFilter] }
           : projectFilter;