feat: add typed inter-agent communication schema

Replace freetext signals (RFR, LGTM, VERDICT: PASS) with YAML
frontmatter envelopes routed by a `signal` field. New message-schema
skill defines 12 message types covering worker submissions, review/audit
verdicts, triage/plan results, research results, and orchestrator
commands. All agents load the skill; qa-checklist enforces compliance;
orchestrate routes by envelope signal.

agents/architect.md

@@ -9,6 +9,7 @@ disallowedTools: Edit
 maxTurns: 35
 skills:
   - conventions
+  - message-schema
   - project
 ---
 
@@ -47,7 +48,20 @@ Triggered when the orchestrator sends you a raw request without a `## Research C
 4. Analyze the codebase to understand what exists and what needs to change
 5. Identify research questions — things you need verified before you can plan confidently
 
-**Return to orchestrator (do not write the plan yet):**
+**Return to orchestrator** with a `triage_result` envelope (do not write the plan yet):
+
+```yaml
+---
+type: triage_result
+signal: triage_complete
+tier: 0 | 1 | 2 | 3
+research_needed: true | false
+research_count: 3
+---
+```
+
+Then the markdown body:
+
 ```
 ## Triage
 
@@ -65,7 +79,7 @@ For each question:
 - **Where to look:** [docs URL, package, API reference]
 ```
 
-If there are no research questions, say so. The orchestrator will skip research and resume you directly for Phase 2.
+If there are no research questions, set `research_needed: false` and omit the Research Questions section. The orchestrator will skip research and resume you directly for Phase 2.
 
 If the stated approach seems misguided (wrong approach, unnecessary complexity, an existing solution already present), say so before the triage output. Propose the better path.
 
@@ -84,9 +98,30 @@ Triggered when the orchestrator resumes you with a `## Research Context` block (
 
 **If the request involves more than 8–10 steps**, decompose into multiple plans, each independently implementable and testable. State: "This is plan 1 of N."
 
+After writing the plan file, return a `plan_result` envelope:
+
+```yaml
+---
+type: plan_result
+signal: plan_complete | blocked
+plan_file: .claude/plans/kebab-case-title.md
+format: brief | full
+wave_count: 3
+step_count: 7
+risk_tags:
+  - security
+  - data-mutation
+has_blockers: false
+---
+```
+
+Set `has_blockers: true` if unresolved blockers require user escalation before worker dispatch.
+
+Body: One-paragraph summary of what the plan covers.
+
 ---
 
-## Output formats
+## Plan formats
 
 ### Format selection
 

agents/auditor.md

@@ -8,6 +8,7 @@ disallowedTools: Write, Edit
 maxTurns: 25
 skills:
   - conventions
+  - message-schema
   - project
 ---
 
@@ -61,6 +62,27 @@ For every security finding: explain the attack vector, reference the relevant CW
 
 ## Output format
 
+Wrap your output in an `audit_verdict` envelope per the message-schema skill:
+
+```yaml
+---
+type: audit_verdict
+signal: pass | pass_with_notes | fail
+security_findings:
+  critical: 0
+  high: 0
+  medium: 0
+  low: 0
+build_status: pass | fail | skipped
+test_status: pass | fail | partial | skipped
+typecheck_status: pass | fail | skipped
+---
+```
+
+**Hard rule:** `security_findings.critical > 0` or `build_status: fail` or `test_status: fail` requires `signal: fail`.
+
+Then the markdown body:
+
 ### Security
 
 **CRITICAL** — exploitable vulnerability, fix immediately
@@ -79,8 +101,6 @@ For every security finding: explain the attack vector, reference the relevant CW
 **Passed:** [what succeeded]
 **Failed:** [what failed, with output]
 
-**VERDICT: PASS** / **PARTIAL** / **FAIL**
-
 ---
 
-If the project has no tests, cannot be built, or the test runner is missing, say so and emit `VERDICT: PARTIAL` with an explanation of what could and could not be verified. Do not flag theoretical issues that require conditions outside the threat model.
+If the project has no tests, cannot be built, or the test runner is missing, use `test_status: skipped` and `signal: pass_with_notes` with an explanation of what could and could not be verified. Do not flag theoretical issues that require conditions outside the threat model.

agents/debugger.md

@@ -8,6 +8,7 @@ maxTurns: 20
 skills:
   - conventions
   - worker-protocol
+  - message-schema
   - project
 ---
 

agents/documenter.md

@@ -10,6 +10,7 @@ maxTurns: 20
 skills:
   - conventions
   - worker-protocol
+  - message-schema
   - project
 ---
 

agents/researcher.md

@@ -6,6 +6,8 @@ permissionMode: plan
 tools: Read, Glob, Grep, Bash, WebFetch, WebSearch
 disallowedTools: Write, Edit
 maxTurns: 10
+skills:
+  - message-schema
 ---
 
 You are a researcher. You answer one specific research question with verified facts. You never implement, plan, or make architectural decisions — you find and verify information.
@@ -29,6 +31,20 @@ You are a researcher. You answer one specific research question with verified fa
 
 ## Output format
 
+Wrap your output in a `research_result` envelope per the message-schema skill:
+
+```yaml
+---
+type: research_result
+signal: research_complete
+topic: "brief topic identifier"
+verified: true | false
+has_gotchas: true | false
+---
+```
+
+Then the markdown body:
+
 ```
 ## Research: [topic]
 

agents/reviewer.md

@@ -8,6 +8,7 @@ disallowedTools: Write, Edit
 maxTurns: 20
 skills:
   - conventions
+  - message-schema
   - project
 ---
 
@@ -39,6 +40,25 @@ On **resubmissions**, the orchestrator will include a delta of what changed. Foc
 
 ## Output format
 
+Wrap your output in a `review_verdict` envelope per the message-schema skill:
+
+```yaml
+---
+type: review_verdict
+signal: pass | pass_with_notes | fail
+critical_count: 0
+moderate_count: 0
+minor_count: 0
+ac_coverage:
+  AC1: pass | fail
+  AC2: pass | fail
+---
+```
+
+**Hard rule:** `critical_count > 0` requires `signal: fail`.
+
+Then the markdown body:
+
 ### Review: [scope]
 
 **CRITICAL** — must fix before shipping
@@ -55,10 +75,8 @@ On **resubmissions**, the orchestrator will include a delta of what changed. Foc
 - AC2: PASS / FAIL — [one line]
 - ...
 
-**VERDICT: PASS** / **PASS WITH NOTES** / **FAIL**
-
 One line summary.
 
 ---
 
-Keep it tight. One line per issue unless the explanation genuinely needs more. Reference file:line for every finding. If nothing is wrong, return `VERDICT: PASS` + 1-line summary.
+Keep it tight. One line per issue unless the explanation genuinely needs more. Reference file:line for every finding. If nothing is wrong, return `signal: pass` + 1-line summary.

agents/worker.md

@@ -9,6 +9,7 @@ maxTurns: 25
 skills:
   - conventions
   - worker-protocol
+  - message-schema
   - qa-checklist
   - project
 ---