[JFWooten4]

Problem

Every click of Summarize with ChatGPT sends a new attachment for the same PDF, creating (1), (2), and other duplicate Library entries.

Fix

• Compute a SHA-256 digest of PDF contents (not a filename or URL) before selecting a destination.
• On the first request, upload normally and remember the conversation URL after ChatGPT creates it.
• On subsequent requests for identical PDF bytes, reopen that conversation with a new prompt without uploading again.
• When an upload is still in progress, focus its existing tab instead of starting another.
• Shift-click always starts a separate new chat and upload, leaving the saved reuse mapping untouched.
• Do not reuse attachments for modified documents, and clear stale/failed in-progress mappings.

This reuses the existing conversation rather than automating ChatGPT's undocumented Library picker, and it does not delete previously created duplicates.

Reliable submission, including background tabs

• Fill the summary prompt as soon as the ChatGPT composer is available, before receiving the PDF through the extension relay.
• After the file input accepts the attachment, wait only for the attachment chip, not for upload progress indicators to disappear; then press Send and let ChatGPT queue processing until upload finishes.
• Re-fill the composer if ChatGPT's editor is replaced during hydration, allow hidden tabs to submit without layout rects, and suspend wait timeouts when backgrounded.
• Keep pending handoffs and conversation URL tracking available for up to ten minutes rather than silently failing after two minutes.
• Add tests/chatgpt-summary-handoff.test.mjs covering pre-upload composition, sending with upload progress active, hidden tabs, hydration and reuse, plus a delayed-pending regression.

Verification

• Reviewed generated Git tree to confirm all four intended files changed, parsed the modified JavaScript, and exercised mocked fresh, reused, pending, and Shift-click paths.
• Added regression tests for those paths in tests/chatgpt-summary-popup.test.mjs.
• GitHub Actions passed after the initial duplicate-attachment changes and after the early-submit changes. Final background-timeout follow-up CI is pending. A live ChatGPT end-to-end test remains unverified; the site's DOM and routing may change.