fix(github): cap unbounded backfill list pagination at 10 pages (#8890)

[andriypolanski]

Summary

• Closes fix(github): three GitHub list-pagination loops in backfill.ts have no page cap, unlike every sibling loop in the same file #8890
• Adds GITHUB_LIST_MAX_PAGES = 10 for syncLabels, supplementOpenIssuesFromGraphQl, and supplementOpenPullRequestsFromGraphQl — matching the file’s existing 10-page convention.
• Cap hits surface a capped segment status (labels) or a cap-matching warning (GraphQL supplements), consistent with githubPaged.
• Regression tests assert the loop stops at page 10 without relying on a mocked hasNextPage: false.

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 a currently open issue this PR resolves (e.g. Closes #123) — a linked open issue is required for every contributor PR.

Validation

• git diff --check
• npx vitest run test/unit/backfill.test.ts -t "#8890" — 2 passed
• Related existing tests (late pagination, endCursor, unauthenticated labels fallback) — passed
• npm run actionlint
• npm run typecheck
• npm run test:coverage
• 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:

Narrow pagination-bound fix in src/github/backfill.ts; full test:ci left for the opener before push.

Notes for reviewers / gate

• No secrets, wallets, hotkeys, trust scores, or reward values.
• Does not touch site/, CNAME, **/lovable/**, or CHANGELOG.md.
• No UI Evidence (backend-only).

[superagent-security]

Superagent didn't find any vulnerabilities or security issues in this PR.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.86%. Comparing base (401caef) to head (add8bda).
⚠️ Report is 14 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8963      +/-   ##
==========================================
+ Coverage   90.56%   90.86%   +0.30%     
==========================================
  Files          96       97       +1     
  Lines       22490    23861    +1371     
  Branches     3884     4415     +531     
==========================================
+ Hits        20367    21681    +1314     
- Misses       1945     1952       +7     
- Partials      178      228      +50     

Flag	Coverage Δ
backend	95.84% <100.00%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/github/backfill.ts	95.84% <100.00%> (ø)

[loopover-orb]

Tip

✅ LoopOver review result - approve/merge recommended

_{Review updated: 2026-07-26 14:47:50 UTC}

2 files · 1 AI reviewer · no blockers · readiness 95/100 · CI green · clean

✅ Suggested Action - Approve/Merge

• safe to merge

Review summary
This PR closes #8890 by capping three previously-unbounded pagination loops (syncLabels, supplementOpenIssuesFromGraphQl, supplementOpenPullRequestsFromGraphQl) at GITHUB_LIST_MAX_PAGES=10, matching the file's existing 10-page convention (e.g. PR_DETAIL_MAX_PAGES, SEGMENT_PAGE_BUDGET). Cap hits correctly surface as a `capped` segment status for labels (with pageCount/nextCursor wired into completeSegment) and as push-to-`warnings` messages for the GraphQL supplements, and the two new regression tests actually drive the loop to page 10 via real hasNextPage:true responses rather than mocking termination — a legitimate real-path test, not a fabricated one. The change is narrow, well-scoped to the issue, and the wiring (supplementOnUnderCount now threading a shared `warnings` array through to the two supplement functions) is consistent end-to-end.

Nits — 5 non-blocking

• src/github/backfill.ts:4436-4470 (syncLabels): unlike githubPaged's `nextCursor = undefined` reset when status is complete, here `nextCursor` is only ever set on the capped branch, which is correct, but consider a comment noting parity with githubPaged's page-cap-vs-item-cap distinction for future maintainers touching this function.
• The removed `/* v8 ignore start/stop */` blocks around supplementOpenIssuesFromGraphQl/supplementOpenPullRequestsFromGraphQl (src/github/backfill.ts:1791-1794, 1845ish) are appropriate now that real tests exercise these paths, but double check the remaining defensive-normalization branches inside those functions (malformed node shapes) still have coverage since the ignore pragma removal expands what coverage now expects.
• Nice touch that the test at test/unit/backfill.test.ts uses a real Link-header-driven pagination loop for syncLabels instead of asserting call count only, matching the trace-to-source review guidance for this repo.
• Consider extracting the repeated 'reached local page cap of N' warning-push pattern (labels, open-issues, open-pull-requests) into a small shared helper to avoid drift if the message format needs to change again across all three sites.
• Verify with `npm run test:coverage` (marked unchecked in the PR) that the new capped branches hit the ~97% patch coverage bar, particularly the `status === "capped"` vs `"complete"` expectedCount ternary in syncLabels.

Decision drivers

• ✅ Code review — No blockers (1 reviewer)
• ✅ Gate result — Passing (No configured blocker found.)

Context & advisory signals — never blocks the verdict

Signal	Result	Evidence
Linked issue	✅ Linked	#8890
Related work	✅ No active overlap found	No same-issue or scoped active PR overlap found.
Change scope	✅ 20/20	Low review scope from cached public metadata (1 linked issue).
Validation posture	✅ 25/25	PR body includes validation/test evidence.
Contributor workload	✅ 10/10	Author activity: 200 registered-repo PR(s), 126 merged, 22 issue(s).
Contributor context	✅ Confirmed Gittensor contributor	andriypolanski; Gittensor profile; 200 PR(s), 22 issue(s).
Improvement	✅ Minor	risk: clean · value: minor · LLM: moderate

Linked issue satisfaction

Addressed
The diff adds a shared GITHUB_LIST_MAX_PAGES = 10 constant and applies it to all three previously unbounded loops (syncLabels, supplementOpenIssuesFromGraphQl, supplementOpenPullRequestsFromGraphQl), each surfacing a capped status/warning consistent with the file's existing convention, and includes regression tests asserting the loops stop at page 10 with capped signals rather than relying on mock

Review context

• Author: andriypolanski
• Role context: outside_contributor
• Public audience mode: oss maintainer
• Lane context: Repository is configured for direct PR review.
• Public profile languages: not available
• Official Gittensor activity: 200 PR(s), 22 issue(s).
• PR-specific overlap: none found.

Contributor next steps

• Start here: Triage stale or unlinked PRs.

Signal definitions

• Related work = same linked issue, overlapping active PRs, or title/path similarity.
• Change scope = cached public metadata such as size labels, draft state, and review-burden hints.
• Validation posture = whether the PR provides enough public validation/test evidence for maintainer review.
• Contributor workload = public contributor activity and cleanup pressure, not a repo-wide quality failure.
• Contributor context = public GitHub/Gittensor identity context; non-Gittensor status is not a blocker.

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_{🟩 Safe / merged · 🟦 Advisory · 🟨 Held for review · 🟥 Blocked / closed}

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LoopOver approves — the gate is satisfied and CI is green.