fix(reliability): Address 12 review issues across circuit breaker, DLQ, config merge, and CLI

docs/HUMAN_REVIEW.md

@@ -0,0 +1,147 @@
+# Human Review Gates — Reliability
+
+Every reliability feature includes human review steps. The system **never** silently changes behavior, retries destructively, or masks failures.
+
+> **The system does work. The human makes decisions.**
+
+- Retries within limits → automatic (but visible)
+- Recovery, replay, escalation → always human-approved
+- Failures → always surfaced with context and options
+- No silent state changes that affect mesh behavior
+
+See [reliability.md](./reliability.md) for feature details.
+
+---
+
+## Nine 1 — Basic Error Handling
+
+### Worker Retries
+- When retries exhaust → DLQ entry created → core presents failure to user
+- User decides: retry with variation, recover from checkpoint, or drop
+
+### Injection Poll Loop
+- Stale entries (>5min) are dropped but remain available via `tx inbox`
+- If file-based fallback activates, user sees pending messages on next interaction
+
+### Routing Correction
+- When routing retries exhaust → escalated to user with full attempt history
+- User sees which targets were tried and picks correct one
+
+### Usage Policy Errors
+- Human chooses: retry, skip, modify prompt, or abort
+- Full diagnostic context (triggering prompt, recent history) included in ask-human message
+
+### Recovery Handler
+- First 2 recovery requests: automatic guidance with FSM state and valid routes
+- 3rd+ request in 60s: escalated to human — agent is repeatedly stuck
+
+---
+
+## Nine 2 — Validation & Protocol Enforcement
+
+### Parity Gate
+- Violations → reminder injected to agent
+- If unresolved after reminder → surfaced to user with pending asks list
+
+### Identity Gate
+- Kill events → logged with full reason (agent ID, expected vs actual `from:` field)
+- User can audit identity violations via logs
+
+### Mesh Validator
+- Validation errors → block mesh load, user sees what's wrong and how to fix it
+- Warnings → logged but don't block (user can review in logs)
+
+### Manifest Validator
+- Validation failures → surfaced to user with missing/invalid paths and responsible agents
+
+### Bash Guard
+- 1-2 violations → error response with allowed paths shown to agent
+- 3+ violations → worker killed, logged for forensics
+- User can audit bash guard events in logs
+
+---
+
+## Nine 2.5 — Self-Healing & Auto-Recovery
+
+### Nudge Detector
+- Nudges are logged and visible in `tx spy`
+- Max 1 nudge per agent prevents recovery loops
+
+### Deadlock Breaker
+- Shallow cycles (depth ≤ 3) → auto-broken, logged
+- Deep cycles (depth 5+) → escalated to human with cycle visualization (A→B→C→A)
+- User decides which agent's ask to drop
+
+### Stale Message Cleaner
+- Stale messages archived with reason — no silent deletion
+- User can audit via `tx spy` and review archived messages
+
+### Quality Iteration Loops
+- Max iterations hit → presents feedback history to user
+- User decides: retry, accept current output, or drop
+- Each iteration's feedback is visible for review
+
+---
+
+## Nine 3 — Monitoring, Circuit Breaking, DLQ
+
+### Circuit Breaker
+- Circuit open → agent skipped, logged with failure count
+- Half-open test spawn → user can monitor via `tx mesh health`
+- Circuits don't auto-close silently — health dashboard shows state
+
+### Heartbeat Monitor
+- Warn threshold → logged warning (no action)
+- Stale threshold → logged stale warning
+- Dead threshold → **worker killed**, failure recorded, routed to DLQ
+- All events visible in `tx mesh health` with silence duration
+
+### Dead Letter Queue
+- **Recovery always requires human review** (except crash recovery on restart)
+- Core agent diagnoses, presents options (resume vs rewind vs drop), gets explicit confirmation
+- Available checkpoints shown before any recovery action
+- `tx mesh dlq` shows all pending entries with recovery mode and context
+
+### Checkpoint Log & Rewind-To
+- Checkpoint notification: core can surface "Mesh X completed 'build' — checkpoint saved"
+- Before rewind-to replay, core presents: which checkpoint, what replays, what's discarded
+- Post-replay: result presented for user approval before mesh continues
+- **Replay never happens without user choosing a checkpoint**
+
+### SLI Tracker
+- Threshold alerts: "Mesh X reliability dropped to 94.2% (below 95% cautious threshold). 3 failures in last 10 runs. Categories: 2x model_error, 1x timeout."
+- Periodic health summary available via `tx mesh health`
+- SLI data always visible — never hidden from user
+
+### Safe Mode
+- **Escalation beyond cautious requires user confirmation** when surfaced via core
+- Auto-escalation (if enabled) is logged with reason and SLI data
+- **Never auto-de-escalates** — human must clear via `resetMesh()` or `resetAll()`
+- Core presents: "SLI recovered to 98%. Clear restricted mode for mesh X?"
+
+---
+
+## Roadmap — Nine 4
+
+### Retry-With-Variation
+- First failure: core reports "Agent X failed (model_error). Retrying with variation: [description]. Retry 1/3."
+- Each retry logs what changed (e.g., "retry 2: simplified prompt, dropped optional context")
+- Exhausted retries: core presents full retry history with variations tried — user decides next step
+- New variation strategies require review before taking effect
+
+### Output Schema Validation
+- Validation failure: core reports "Agent X output failed validation: missing required field 'summary'."
+- Before retry with validation feedback, core presents: "Ask agent X to fix? Validation errors: [list]. Or drop?"
+- Schema changes in mesh config: core surfaces impact on existing agents
+- Partial pass: core shows what passed/failed, user decides accept partial, retry, or drop
+
+### Critical/Non-Critical Agent Classification
+- On mesh load, core can surface classifications: "critical=[planner, builder], non-critical=[linter]"
+- Non-critical failure: "Agent 'linter' failed (timeout). Mesh continues. Output from this step missing."
+- Repeated non-critical failures: "Agent 'linter' failed 5 times. Promote to critical or disable?"
+- Critical failures always stop the mesh and present recovery options
+
+### Aggregate Observability Dashboard
+- Anomaly alerts: "Mesh X failure rate spiked from 2% to 15% in last hour. Category: model_error."
+- Cost review gate: "Recovering mesh X with rewind-to will replay ~50k tokens. Proceed?"
+- Dashboard is passive — all actions from insights go through standard human review