fix: resolve golangci-lint errors

- Add error check for fmt.Fprintf in tips.go (errcheck)
- Add nolint for safe SQL formatting in transaction.go (gosec G201)
- Fix 'cancelled' -> 'canceled' spelling (misspell)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

internal/storage/sqlite/util.go

@@ -84,7 +84,7 @@ func IsBusyError(err error) bool {
 //   - initialDelay: initial backoff delay (default: 10ms)
 //
 // Returns error if:
-//   - Context is cancelled
+//   - Context is canceled
 //   - BEGIN IMMEDIATE fails with non-busy error
 //   - All retries exhausted with SQLITE_BUSY
 func beginImmediateWithRetry(ctx context.Context, conn *sql.Conn, maxRetries int, initialDelay time.Duration) error {