[Douglasymlai]

Pull Request

Related Issue

N/A — maintainer-directed repair; no linked issue required for this PR.

Description

Problem

The native PDF viewer displayed a generic “stream” title and could exceed a narrow preview pane.

Change

Give authorized local and streamed PDF URLs a filename path, retain the original file identity in the query, send an inline filename header for local responses, and default the native viewer to fit width. The preview can shrink within its pane while preserving native controls and byte ranges. Updated against current main.

Testing Evidence (REQUIRED)

• 38 focused frontend tests and 15 backend file-controller tests passed, including Unicode filenames, signed URLs, explicit zoom, range responses, and frame failure/retry.
• Type checking, focused ESLint/Prettier, and git diff --check passed.
• Real Electron 33 runtime: production PdfPreview and the extracted production local-file protocol handler displayed “Quarterly report 中文.pdf”; both page edges remained visible at 740px and 420px pane widths and after returning to wide.
• Existing iframe/preview layout retained; existing third-party-viewports exception used. No new primitives, semantic tokens, or exceptions.
• Full packaged app, password-protected documents and the full theme/zoom matrix were not exercised.
• Follow-up fix: a preview URL that cannot be parsed is passed through unchanged instead of throwing. 33 frontend tests pass.

Automated checks only; manual app testing is pending.

• I have included human-verified testing evidence in this PR.
• This PR includes frontend/UI changes, and I attached screenshot(s) or screen recording(s).
• No frontend/UI changes in this PR.

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

Contribution Guidelines Acknowledgement

• I have read and agree to the Eigent Contribution Guideline