fix: receipt machinery enforce-readiness (S404 dogfood findings)

[Nazim22]

What

Closes the S404 advisory-dogfood defects (issues #18, #9-partial):

• init --mode advisory|enforce; --dry-run now writes nothing (planClaudeCodeInstall)
• Obligation extraction skips system-injected spans (task-notifications, system-reminders, prior [LEADLINE] blocks)
• Unsatisfiable obligations abstain: nonexistent correction target → immediate ABSTAIN; else 3rd corrective fire or 15-min age → one append-only ABSTAIN row (failure: unsatisfiable, fire count), obligation retired, call proceeds — enforce can never permanently lock a tool
• Correction budget keyed on the obligation (rule.id), not the invocation — proven against the real S404 pattern (varying commands + fresh tool_use_id per call); budget resets on genuine satisfaction/approval
• Trace rows schema-validated at write (no empty attempted/null rule_id)
• Injection context bounded (1200-byte cap, word-safe truncation)
• CI smoke actually exercises the init path (the --help || short-circuit is gone)

Review

Built by Daedalus (dae/ll-s404-receipt-fixes, base 0218f52). Reviewed at 5e9c6f5 — one blocker (invocation-keyed budget, executable repro) — corrected additively in e88fbc2, re-reviewed and re-proven: repro shows DENY→ASK→ABSTAIN→ALLOW on all production shapes; 250/250.

🤖 Generated with Claude Code