feat: Initial clean release of CHM

packages/lib/services/database/migrations/52.ts

@@ -0,0 +1,32 @@
+import { SqlQuery } from '../types';
+
+// Storage for the AI embeddings index. Two tables:
+//
+// - `note_embeddings_meta` holds the per-chunk metadata. It is a regular table
+//   so the metadata (chunk text, source note ID, model identifier) can be
+//   inspected and managed even on platforms where the sqlite-vec extension
+//   isn't available.
+//
+// - `note_embeddings_vec` is the sqlite-vec virtual table holding the actual
+//   vectors. It is created lazily by the embeddings code when sqlite-vec is
+//   available, because virtual-table syntax differs by extension version and
+//   trying to create it unconditionally would break startup on platforms
+//   without the prebuilt.
+//
+// Neither table is synced — embeddings are large, model-specific, and easily
+// re-derivable on demand.
+
+export default (): (SqlQuery|string)[] => {
+	return [
+		`CREATE TABLE IF NOT EXISTS note_embeddings_meta (
+			id INTEGER PRIMARY KEY AUTOINCREMENT,
+			note_id TEXT NOT NULL,
+			chunk_index INTEGER NOT NULL,
+			model_id TEXT NOT NULL,
+			chunk_text TEXT NOT NULL,
+			created_time INT NOT NULL DEFAULT 0
+		)`,
+		'CREATE INDEX IF NOT EXISTS note_embeddings_meta_note_id ON note_embeddings_meta(note_id)',
+		'CREATE UNIQUE INDEX IF NOT EXISTS note_embeddings_meta_note_chunk ON note_embeddings_meta(note_id, chunk_index)',
+	];
+};