Merge origin/main into local EFX governance work

Keep EFX-001..003 runtime guards and the incoming ADR32 evidence/receipt
parity opt-in. Overlapping run_evidence/run_receipt files already matched
both sides; EFX tests, analysis, and risk review remain.

Action: G-P0-2
Constraint: merge-only; existing seams; no second framework; no exactly-once claim; no live GitHub/browser/provider mutation
Tested: focused pytest 50 passed (run_evidence, run_receipt, efx001-003, durable-effect adoption guard)
Not-tested: full suite; live GitHub/browser/paid providers; production deploy
Confidence: high
Roadmap-Status: unchanged

Author: johnteee