feat: Bootstrap orchestrator learnings with investigation queue

MS-SEC-001 shows -98% variance (15K→0.3K) - flagged for investigation.
Possible causes: auth pre-existed, trivial decorator, or reporting error.

docs/orchestrator-learnings.json

@@ -0,0 +1,40 @@
+{
+  "project": "mosaic-stack",
+  "milestone": "M6-AgentOrchestration",
+  "created_at": "2026-02-05T20:00:00Z",
+  "learnings": [
+    {
+      "task_id": "MS-SEC-001",
+      "task_type": "AUTH_ADD",
+      "estimate_k": 15,
+      "actual_k": 0.3,
+      "variance_pct": -98,
+      "characteristics": {
+        "file_count": 1,
+        "keywords": ["authentication", "orchestrator API", "ApiKeyGuard"]
+      },
+      "analysis": "CRITICAL VARIANCE - Investigate. Possible causes: (1) Auth already existed, (2) Task was trivial decorator addition, (3) Reporting error. Need to verify task completion quality.",
+      "flags": ["CRITICAL", "NEEDS_INVESTIGATION"],
+      "captured_at": "2026-02-05T15:30:00Z"
+    }
+  ],
+  "phase_summaries": [],
+  "proposed_adjustments": [
+    {
+      "category": "AUTH_ADD",
+      "current_heuristic": "15-25K",
+      "proposed_heuristic": "PENDING INVESTIGATION",
+      "confidence": "LOW",
+      "evidence": ["MS-SEC-001"],
+      "notes": "-98% variance is anomalous. Do not update heuristic until root cause understood."
+    }
+  ],
+  "investigation_queue": [
+    {
+      "task_id": "MS-SEC-001",
+      "question": "Did this task actually add authentication, or was auth already present?",
+      "priority": "HIGH",
+      "status": "OPEN"
+    }
+  ]
+}