Add deterministic triage prep evidence

[ericlitman]

Summary

Backlog-manager triage can now consume a fresh, deterministic evidence sheet for every candidate before spending model judgment. The flag-gated transform checks cited anchors against each repository's current origin/main, surfaces typed-class emission as a weak signal, joins prior council adjudications, reports recurrence and family context, and writes only ephemeral run artifacts.

The live calibration covers the three legacy cases named by SYMPH-1148: MOB-1150 is grouped into its shared-class family, MOB-1148 carries the overlapping-ledger Track downgrade, and MOB-1147 reports post-filing anchor movement. A separate Triage run found nine current crucible.findings-intake.v2 sheets; because the installed v2 schema provides deterministic identity but no exact numeric recurrence fields, those sheets report visible same-fkey recurrence as partial instead of inventing counters.

The stage remains read-only and report-only. It integrates through the existing manager context transform and standing shadow-plan path, and records mutationPolicy: read_only_no_linear_writes in each artifact.

The SYMPH-1165 review fix also verifies symbol-only anchor fingerprints against fresh file contents, so a surviving path with a removed symbol is reported as gone and its family is no longer treated as fully live.

Validation

Current head 26dacd97c2b80d336213da9d229c0bc2522da6d5:

• pnpm exec vitest run tests/orchestrator/triage-prep.test.ts — 14/14 passed
• pnpm typecheck
• pnpm build
• pnpm lint
• pnpm architecture:check
• pnpm docs:check
• semgrep scan --config p/default --config p/typescript --baseline-commit a2af428b --error --text — 0 findings
• Full-suite known-failure procedure exhausted without a retry loop: the initial unrelated app-server stall test passed in isolation; the single exact-command recovery then timed out in the unrelated code-grounding file-cap test. The recurrence is recorded on SYMPH-358. The immediately preceding reviewed head passed 231 files and 4,636 tests, and the current focused/product gates are clean.
• Live Done calibration — 740 sheets, no warnings, fresh Crucible origin/main at 8ccf119c03f49ef3fd98b0ed24c17b11d8c38f44
• Live Triage calibration — 282 sheets, including 9 current findings-intake v2 sheets, no warnings

Linear: SYMPH-1148, SYMPH-1165

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