fix: PRAGMA defer_foreign_keys must run BEFORE batch transaction

SQLite rule: PRAGMA foreign_keys/defer_foreign_keys cannot be
changed inside a transaction. D1 batch() is an implicit transaction.

Previous fix put PRAGMA inside the batch where it had no effect.
Now runs PRAGMA defer_foreign_keys = ON as a separate .run()
call before the batch, which correctly defers FK checks for
the duration of the batch transaction.

Author: CloudLobster

worker/src/routes/register.ts

@@ -301,9 +301,11 @@ registerRoutes.put('/upgrade', authMiddleware(), async (c) => {
     return c.json({ error: 'This Basename handle is already registered by another wallet' }, 409);
   }
 
-  // 更新帳號 handle + 遷移所有 FK 子表（D1 不支援 PRAGMA defer_foreign_keys）
+  // 更新帳號 handle + 遷移所有 FK 子表
+  // SQLite: PRAGMA defer_foreign_keys must be set BEFORE the transaction starts.
+  // D1 batch() is an implicit transaction, so PRAGMA goes before it.
+  await c.env.DB.prepare("PRAGMA defer_foreign_keys = ON").run();
   const batchResults = await c.env.DB.batch([
-    c.env.DB.prepare("PRAGMA foreign_keys = OFF"),
     // 1. 更新主表
     c.env.DB.prepare(
       'UPDATE accounts SET handle = ?, basename = ? WHERE wallet = ?'
@@ -348,9 +350,8 @@ registerRoutes.put('/upgrade', authMiddleware(), async (c) => {
     c.env.DB.prepare(
       'UPDATE escrow_claims SET claimer_handle = ? WHERE claimer_handle = ?'
     ).bind(newHandle, oldHandle),
-    c.env.DB.prepare("PRAGMA foreign_keys = ON"),
   ]);
-  const migratedCount = batchResults[2]?.meta?.changes || 0;
+  const migratedCount = batchResults[1]?.meta?.changes || 0;
 
   // Insert into basename_aliases with is_primary=1
   if (basenames) {

worker/src/routes/settings.ts

@@ -185,9 +185,10 @@ settingsRoutes.put('/primary', async (c) => {
     return c.json({ error: 'Handle already taken by another wallet' }, 409);
   }
 
-  // Batch update: switch primary（更新所有 FK 子表，D1 不支援 defer_foreign_keys）
+  // Batch update: switch primary（更新所有 FK 子表）
+  // SQLite: PRAGMA defer_foreign_keys must be set BEFORE the transaction starts.
+  await c.env.DB.prepare("PRAGMA defer_foreign_keys = ON").run();
   await c.env.DB.batch([
-    c.env.DB.prepare("PRAGMA foreign_keys = OFF"),
     // Update account handle
     c.env.DB.prepare('UPDATE accounts SET handle = ?, basename = ? WHERE wallet = ?')
       .bind(newHandle, alias.basename, auth.wallet),
@@ -224,7 +225,6 @@ settingsRoutes.put('/primary', async (c) => {
     // Set new primary
     c.env.DB.prepare('UPDATE basename_aliases SET is_primary = 1 WHERE handle = ? AND wallet = ?')
       .bind(newHandle, auth.wallet),
-    c.env.DB.prepare("PRAGMA foreign_keys = ON"),
   ]);
 
   // Issue new token