feat(extension): detect GitHub issue pages

[mkdev5]

Summary

• Closes feat(extension): scaffold GitHub overlay browser extension #145.
• Extend the MV3 content-script scaffold so GitHub issue pages are detected alongside PR pages.
• Preserve the existing behavior that only PR pages mount the private overlay or call the pull-context API; issue pages are recognized as scaffold targets without adding UI, comments, source upload, or duplicated intelligence logic.

Scope Summary

This PR only updates extension URL detection, the MV3 content-script match list, and focused content-script tests. It does not add visible extension UI states, does not rebuild or commit the downloadable extension zip, does not change extension auth/API behavior, and does not touch docs, dependencies, backend, or release notes.

Scope

• The PR title follows type(scope): short summary Conventional Commit format, for example fix(api): restore profile access checks.
• This PR is focused and does not mix unrelated backend, UI, MCP, docs, dependency, and deploy changes.
• This follows CONTRIBUTING.md and does not reintroduce GitHub Pages, VitePress, site/, or CNAME.
• I linked an issue, or this is small enough that the summary explains why an issue is not needed.

Validation

• git diff --check
• npm run actionlint
• npm run typecheck
• npm run test:coverage locally; global coverage stays at or above 97% for lines, statements, functions, and branches (aim for 98%+ branch coverage locally so CI variance does not fail near the threshold)
• npm run test:workers
• npm run build:mcp
• npm run test:mcp-pack
• npm run ui:openapi:check
• npm run ui:lint
• npm run ui:typecheck
• npm run ui:build
• npm audit --audit-level=moderate
• New or changed behavior has unit/integration tests for new branches, fallback paths, and sanitizer boundaries

If any required check was skipped, explain why:

• None. npm run test:ci passed locally after rerunning outside the sandbox. A first sandboxed coverage attempt hit known MCP/local-scorer sandbox failures and was discarded.
• Targeted checks also passed: npm run test -- test/unit/extension-content.test.ts test/unit/extension-auth.test.ts test/unit/routes-extension.test.ts and npm run typecheck.

Safety

• No secrets, wallet details, hotkeys, coldkeys, user PATs, private keys, raw trust scores, private rankings, or private maintainer evidence are exposed.
• Public GitHub text stays sanitized, low-noise, and does not imply compensation guarantees or optimization tactics.
• Auth, cookie, CORS, GitHub App, Cloudflare, or session changes include negative-path tests.
• API/OpenAPI/MCP behavior is updated and tested where needed.
• UI changes use live API data or real empty/error/loading states, not production mock/demo fallbacks.
• Visible UI changes include a UI Evidence section below with JPG/JPEG or PNG screenshots arranged as organized, captioned, clickable thumbnails. SVG screenshots are not used as review evidence. Review-only screenshots or recordings are not committed to the repository.
• Public docs/changelogs are updated where needed; changelogs are only edited for release-prep PRs.

UI Evidence

No visible UI, frontend, docs, or extension overlay state changed. Issue pages are now detected by the content-script scaffold, but the script intentionally does not mount an issue-page overlay or call a new API. PR overlay rendering is unchanged, so screenshots are not applicable for this non-visible route-detection change.

State / title	JPG/PNG evidence
Not applicable	No visible UI change

Notes

• This is a small replacement for the non-visible scaffold gap left after the prior closed scaffold attempt.
• It deliberately avoids the generated extension zip artifact that blocked the prior closed scaffold attempt.
• Screenshot-backed visible extension states remain separate work for feat(extension): add screenshot-backed v1 review states #243/feat(extension): harden role-based private/public panel rendering #244.

[ghost]

Note

Gittensory Gate skipped

PR closed before full evaluation. No late first comment was created.

Signal	Result	Evidence	Action
Gate result	⚠️ Skipped	#471 is no longer open.	No action.

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Checked by Gittensory, a quiet PR intelligence layer for OSS maintainers.

[JSONbored]

@MkDev11 this is ready from my side.

A few notes:

• Issue pages are detected as scaffold targets while PR pages remain the only overlay mount path.
• The manifest match change is narrow and the content-script tests cover both PR and issue routes.
• Avoiding a committed rebuilt extension zip is the right call for this source-only scaffold change.
• No code changes requested.