Replace String() calls with .toString()/.toLocaleString() per ast-grep rule

- Add formatError() helper in CLI to safely handle unknown error types
- Add uniqueTestId() helper for generating unique test identifiers
- Replace String(id) with id.toString() for database ID conversions
- Replace String(n) with n.toLocaleString() for user-facing number formatting
- Fix TypeScript errors in test files (undefined checks, unused variables)
- Update lint commands to include ast-grep scanning

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/api-server/src/procedures/me/passkeys.ts

@@ -38,7 +38,7 @@ export const renamePasskey = os.me.passkeys.rename
     const result = await context.db
       .updateTable("passkeys")
       .set({ name })
-      .where("id", "=", String(passkeyId))
+      .where("id", "=", passkeyId.toString())
       .where("user_id", "=", context.user.id)
       .executeTakeFirst();
 
@@ -86,7 +86,7 @@ export const deletePasskey = os.me.passkeys.delete
 
       const result = await trx
         .deleteFrom("passkeys")
-        .where("id", "=", String(passkeyId))
+        .where("id", "=", passkeyId.toString())
         .where("user_id", "=", context.user.id)
         .executeTakeFirst();