fix(migrate): make SQLite CREATE TABLE/INDEX statements idempotent before running

Schema drift (tables created outside the migration system) previously caused a
fatal startup crash when drizzle tried to re-create an already-existing table.
Now all CREATE TABLE and CREATE INDEX statements are rewritten with IF NOT EXISTS
before being passed to dialect.migrate, so the error never occurs.

Migration hashes are computed from the original file content and are unaffected
by this transformation, so migration tracking remains correct.

Also adds warn/silly logging to the repair fallback path so future failures
surface a clear reason instead of silently returning false.

Author: mcowger

packages/backend/src/db/migrate.ts

@@ -115,7 +115,12 @@ function attemptSQLiteAlreadyExistsRepair(
 
   // Reach the underlying Bun SQLite Database through the drizzle session
   const sqlite = db?.session?.client;
-  if (!sqlite?.run) return false;
+  if (!sqlite?.run) {
+    logger.warn(
+      'SQLite repair skipped: could not access underlying Database client via db.session.client'
+    );
+    return false;
+  }
 
   sqlite.run(`
     CREATE TABLE IF NOT EXISTS ${DRIZZLE_MIGRATIONS_TABLE} (
@@ -133,7 +138,12 @@ function attemptSQLiteAlreadyExistsRepair(
     const refersToObject = statements.some((s) =>
       s.toLowerCase().replace(/\s+/g, ' ').includes(`\`${objectName}\``)
     );
-    if (!refersToObject) continue;
+    if (!refersToObject) {
+      logger.silly(
+        `SQLite repair: migration ${entry.tag} does not reference ${objectName}, skipping`
+      );
+      continue;
+    }
 
     const alreadyApplied = sqlite
       .query(`SELECT id FROM ${DRIZZLE_MIGRATIONS_TABLE} WHERE hash = ?`)
@@ -249,14 +259,27 @@ export async function runMigrations() {
               await Bun.file(path.join(DEV_MIGRATIONS_DIR.sqlite, 'meta', '_journal.json')).text()
             ) as Journal);
       const migrations = await buildMigrations(journal, DEV_MIGRATIONS_DIR.sqlite);
+      // Make all CREATE TABLE/INDEX statements idempotent before running so that
+      // schema drift (tables created outside the migration system) never causes a
+      // fatal startup failure. The hash field is computed from the original file
+      // content and is not affected by this transformation, so migration tracking
+      // remains correct.
+      const idempotentMigrations = migrations.map((m) => ({
+        ...m,
+        sql: m.sql.map(toIdempotentSQLiteStatement),
+      }));
       try {
-        (db as any).dialect.migrate(migrations, (db as any).session, { migrationsFolder: '' });
+        (db as any).dialect.migrate(idempotentMigrations, (db as any).session, {
+          migrationsFolder: '',
+        });
       } catch (error: any) {
         if (isSQLiteAlreadyExistsError(error)) {
           const repaired = attemptSQLiteAlreadyExistsRepair(db, migrations, journal, error);
           if (repaired) {
             logger.warn('Retrying SQLite migrations after already-exists repair');
-            (db as any).dialect.migrate(migrations, (db as any).session, { migrationsFolder: '' });
+            (db as any).dialect.migrate(idempotentMigrations, (db as any).session, {
+              migrationsFolder: '',
+            });
           } else {
             throw error;
           }