docs: record compat observation auth blocker

dev/ACTIVE_TASK.json

@@ -1 +1 @@
-{"task_file":"dev/tasks/GEN2-DEPLOY-003-isolated-release-slots.json","task_id":"GEN2-DEPLOY-003","task_revision":1}
+{"task_file":"dev/tasks/GEN2-COMPAT-OBS-001-production-compatibility-observation.json","task_id":"GEN2-COMPAT-OBS-001","task_revision":2}

docs/evidence/gen2-compat-obs-001-authenticated-workload-blocked-2026-08-30.json

@@ -0,0 +1,27 @@
+{
+  "task": "GEN2-COMPAT-OBS-001",
+  "status": "BLOCKED_BY_MISSING_CAPABILITY",
+  "timestamp_utc": "2026-08-30T11:20:56Z",
+  "requested_activity": "authenticated representative production workload through the ordinary browser/runtime path",
+  "browser_session": {
+    "initial_state": "one production tab was authenticated",
+    "state_at_message_send": "session expired and the ordinary login page was shown",
+    "credential_handling": "no password, cookie, token or credential was read, copied or used"
+  },
+  "candidate": {
+    "project": "assistant-slot-b",
+    "revision": "216d76f1d8b4eeba6ee9427da4c87c3e5c728c02",
+    "preworkload_smoke": "four components healthy and header canary passed",
+    "telemetry_workload": "not sent"
+  },
+  "rollback": {
+    "control_plane": "Supervisor release rollback",
+    "traffic_mode": "STABLE",
+    "stable_upstream": "http://creator-web:8084",
+    "public_health": 200,
+    "public_ready": 200,
+    "stable_container_ids_changed": false
+  },
+  "missing_capability": "a currently authenticated production session or an already-approved authenticated service acceptance harness; neither may be replaced by reading credentials, cookies or tokens or by creating an authentication bypass",
+  "not_done": ["authenticated workload", "telemetry baseline counters", "observation window start", "observation tag", "V1 retirement"]
+}