Initial release: MCP server enforcing Worker-Reviewer loop

Diligence prevents AI agents from shipping quick fixes that break things
by enforcing a research-propose-verify loop before any code changes.

Key features:
- Worker sub-agent researches and proposes with file:line citations
- Reviewer sub-agent independently verifies claims by searching codebase
- Iterates until approved (max 5 rounds)
- Loads project-specific context from .claude/CODEBASE_CONTEXT.md
- State persisted across sessions

Validated on production codebase: caught architectural mistake (broker
subscriptions on client-side code) that naive agent would have shipped.

test/scenarios/blocking-voice.json

@@ -0,0 +1,78 @@
+{
+  "id": "blocking-voice",
+  "name": "Blocking + Voice Bug",
+  "description": "Fix blocked users can answer DM voice calls",
+
+  "task": "Fix: blocked users can still answer DM voice calls. When user A blocks user B, user B should not be able to answer calls from user A.",
+
+  "naive_fix": {
+    "description": "Add blocking check to answerDmCall()",
+    "changes": [
+      {
+        "file": "src/services/voice-channel.service.ts",
+        "function": "answerDmCall",
+        "change": "Add isBlockingEitherWay check before answering"
+      }
+    ],
+    "issues": [
+      "Doesn't handle block created DURING active call",
+      "Doesn't clean up existing calls when block is created",
+      "Blocked users still receive call notifications"
+    ]
+  },
+
+  "correct_fix": {
+    "description": "Full blocking enforcement following chat.service.ts pattern",
+    "required_changes": [
+      {
+        "file": "src/services/voice-channel.service.ts",
+        "function": "answerDmCall",
+        "change": "Add isBlockingEitherWay check",
+        "line_reference": "line 75"
+      },
+      {
+        "file": "src/services/voice-channel.service.ts",
+        "function": "declineDmCall",
+        "change": "Add isBlockingEitherWay check (consistency)",
+        "line_reference": "line 93"
+      },
+      {
+        "file": "src/services/voice-channel.service.ts",
+        "function": "notifyDmCall",
+        "change": "Filter notifications for blocked users",
+        "line_reference": "line 138"
+      },
+      {
+        "file": "src/services/user-block.service.ts",
+        "function": "blockUser",
+        "change": "Add voice cleanup: endDmCallBetweenUsers()",
+        "line_reference": "line 33"
+      }
+    ],
+    "required_broker_subscriptions": [
+      {
+        "service": "voice-channel.service.ts",
+        "event": "BusUserBlockChange",
+        "action": "Kick users from DM voice when block is created mid-call"
+      }
+    ],
+    "pattern_references": [
+      "chat.service.ts:sendMessage - shows correct action check pattern",
+      "chat.service.ts:getChannelPermission - shows permission vs action separation"
+    ]
+  },
+
+  "validation_criteria": {
+    "must_mention": [
+      "answerDmCall",
+      "BusUserBlockChange",
+      "user-block.service",
+      "notifyDmCall"
+    ],
+    "must_not_change": [
+      "voiceListen permission values",
+      "voiceTalk permission values"
+    ],
+    "should_reference_pattern": "chat.service.ts"
+  }
+}