Sprint 0-2: TS plugin scaffolding, LanceDB utils, tooling updates

- Add index-tool.ts command implementation
- Wire lancedb.ts vector search into plugin
- Update src/tools/index.ts exports
- Bump package deps (ts-jest, jest, typescript, lancedb)
- Add .claude/settings.local.json

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/utils/lancedb.ts

@@ -52,9 +52,6 @@ export async function searchVectorDb(
   }
   const table = await db.openTable("obsidian_chunks");
 
-  // Embed the query text
-  const queryVector = await embedQuery(query, config);
-
   // Build WHERE clause from filters
   const conditions: string[] = [];
   if (options.directory_filter && options.directory_filter.length > 0) {
@@ -79,12 +76,24 @@ export async function searchVectorDb(
 
   const limit = options.max_results ?? 5;
 
-  // LanceDB JS SDK: table.vectorSearch(vector).filter(...).limit(...).toArray()
-  let queryBuilder = table.vectorSearch(queryVector);
-  if (whereClause) {
-    queryBuilder = queryBuilder.filter(whereClause);
+  // Try vector search first; if Ollama is down embedQuery throws → fallback to FTS
+  let rows: Record<string, unknown>[];
+  try {
+    const queryVector = await embedQuery(query, config);
+
+    let queryBuilder = table.vectorSearch(queryVector);
+    if (whereClause) {
+      queryBuilder = queryBuilder.filter(whereClause);
+    }
+    rows = await queryBuilder.limit(limit).toArray();
+  } catch {
+    // Ollama unavailable — fallback to full-text search on chunk_text (BM25 scoring)
+    let ftsBuilder = table.query().fullTextSearch(query);
+    if (whereClause) {
+      ftsBuilder = ftsBuilder.filter(whereClause);
+    }
+    rows = await ftsBuilder.limit(limit).toArray();
   }
-  const rows = await queryBuilder.limit(limit).toArray();
 
   return rows.map((r: Record<string, unknown>) => ({
     chunk_id: r["chunk_id"] as string,
@@ -95,6 +104,6 @@ export async function searchVectorDb(
     date: (r["date"] as string) ?? null,
     tags: (r["tags"] as string[]) ?? [],
     chunk_index: (r["chunk_index"] as number) ?? 0,
-    score: (r["_distance"] as number) ?? 0.0,
+    score: (r["_score"] as number) ?? (r["_distance"] as number) ?? 0.0,
   }));
 }