Motivation

• Downloads could be duplicated because the GM_download mobile timeout and fallback paths were not gated, causing secondary fallback attempts to run after an initial download attempt.
• The change aims to ensure only a single download path runs and to avoid triggering anchor/data-url fallbacks when GM.download has already handled or timed out.

Description

• Bumped pageinfoexport.user.js @version to 2026.01.11.0251 and updated download handling logic in saveWithGMDownload to track fallback state and errors.
• Added new internal flags (fallbackAttempted, allowAutoFallback, lastError) and updated handleError/timer logic to prevent auto-triggering secondary fallbacks on timeout or when fallback already ran.
• Adjusted the calling flow in saveReport to skip the fallback chain when saveWithGMDownload indicates it already attempted fallback or auto-fallback is disabled.

Testing

• No automated tests were run for this change (manual test instructions were included in the commit message).

Codex Task