fix(test): repoint the cadence-signal seed helper from review_targets to pull_requests

[JSONbored]

Problem

main is currently broken for every subsequent PR: test/unit/reputation-wiring.test.ts > shouldSkipAiForReputation (helper) > submission-cadence signal (#4514) > FLAG-ON: true for a machine-paced submitter even though every submission itself looks fine (quality-neutral) fails with expected false to be true.

Root cause

#9041 (merged as c25fa1ef7) correctly repointed getSubmitterCadence's query from review_targets (frozen since the 2026-06-22 self-host cutover — it stopped receiving writes, so the machine-paced signal was silently inert in production) to the live pull_requests ledger.

That PR updated its own new test (test/unit/submitter-reputation.test.ts) to assert the query shape, but missed a sibling: test/unit/reputation-wiring.test.ts's local seedReviewTarget helper (scoped inside the "submission-cadence signal (#4514)" describe block) still inserts rows into review_targets. Since the code now reads pull_requests, that seed produces zero matching rows regardless of what's inserted — getSubmitterCadence always resolves {count: 0, medianGapMs: null}, so isMachinePacedCadence can never return true. The sibling "false for a human pace" test passed vacuously (right answer for the wrong reason); the "true for machine-paced" test asserts true and correctly fails.

Fix

Renamed the local helper to seedCadencePullRequest and repointed it at pull_requests (repo_full_name + author_login, matching the real query). The module-level seedReviewTarget (line 20, used elsewhere in this same file for the quality/burst signal — a separate code path #9041 did not touch) is untouched.

Validation

• npx vitest run test/unit/reputation-wiring.test.ts — 36/36 passed (was 1 failed / 35 passed).
• tsc --noEmit --incremental false clean.
• Diff is a single file, test-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 92.66%. Comparing base (de430a0) to head (6924db0).
⚠️ Report is 2 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9097      +/-   ##
==========================================
+ Coverage   90.56%   92.66%   +2.10%     
==========================================
  Files          96      810     +714     
  Lines       22490    80600   +58110     
  Branches     3884    24454   +20570     
==========================================
+ Hits        20367    74686   +54319     
- Misses       1945     4840    +2895     
- Partials      178     1074     +896     

Flag	Coverage Δ
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