[cschanhniem]

Implements D8 from NEXT_100_PR_MAP: docs/AGENT_FAILURE_MODES.md.

What

• 10 documented failure modes (FM-01 through FM-10): claim escalation, scope creep, benchmark theater, safety weakening, certificate confusion, calibration self-service, hidden dependencies, novelty over-attribution, unsafe parallelism, stop-condition bypass
• Each entry: what it is, why it happens, detection signal, mitigation
• Cross-references check_claims.py, pr_claim_checker.py, cheap_enemy_comparison.py, similarity_neighbor_report.py, PROOF_LADDER.md
• Docs-only PR; no code or test changes

Why

An agent that does not know it can fail is more dangerous than a human who knows they can be wrong. FM-04 (safety weakening by omission) and FM-10 (stop condition ignored) are highest-risk and have been observed in agent loops.

Disconfirming pass

• All 10 failure modes are observable in principle, not hypothetical
• No safety/release policy changed; no threshold or calibration policy touched