ci: master red again -- 8 stale corpus-ledger rows after #10101/#10095, census not re-pinned after #10087 #10171

Boundary

docs/reports/suite_expectations.json (corpus expected-failure ledger) and tools/census/{quiet,shell}.txt (census pins). Also specs/t27mcp/examples.t27, for its duplicate helpers. No workflow change, no compiler change.

Scenarios

Master 45decd5 is red again on two non-required checks, so every open PR inherits them:

1. Corpus ratchet: 8 UNEXPECTED PASSES. spec(igla): make the nine IGLA CODER specs compile and pass with 0 vacuous (Closes #10075) #10101 made seven specs/igla/coder/*.t27 consume every token and spec(nn): make attention.t27 compile and pass with 0 vacuous tests (Closes #10094) #10095 did the same for specs/nn/attention.t27; neither removed its ledger row. bench_proxy and prm fell (738 -> 696, 521 -> 520), and benchmark rose 315 -> 319, all in bdd-block-fallback.
2. cli-tri: census moved. gate(policy): wire pr_budget.t27 into a pull_request_target gate -- draft the 21st open PR, promote held drafts, exempt queen-* (Closes #10074) #10087 added .github/workflows/pr-budget.yml (1 job, 1 run step) without re-pinning: workflow files 66 -> 67, jobs 87 -> 88, run steps 313 -> 314, path-not-quiet 198 -> 200.
3. duplicate-bodies: specs/t27mcp: land examples.t27 and spec_brief.t27 on master #10157 landed specs/t27mcp/examples.t27 with copies of find()/has() taken from check_hints.t27.

Requirements

• examples.t27 imports t27mcp::check_hints instead of carrying its own copies.
• Drop the 8 fixed rows. Re-pin the 3 moved discard counts. Lower the cap to the count, 81 -> 73. Record why in _why_entries_fell / _why_entries_rose, keeping the existing history.
• Re-pin the census with tri census pin --bless and say which numbers moved.

Criteria

• t27c suite --ratchet --corpus-only reports no unexpected pass and no discard drift.
• tri census pin --gate passes.
• CI Corpus ratchet and cli-tri are green on the PR.