fix(dreamer): threshold and time-guard semantics

Finding 2: filter count_stmt on documents.level == 'explicit' in
check_and_schedule_dream. Dreamer-created levels (deductive, inductive,
contradiction) are consolidation output, not input, and would otherwise
inflate the threshold count and create a feedback loop.

Finding 3 (code-level): relocate last_dream_at write from enqueue_dream
(enqueue.py) to process_dream (orchestrator.py), inside the
'if result is not None' block. Duplicate enqueues can no longer reset
the 8-hour time guard clock. Failed/never-run dreams don't advance it.

Success criteria: lenient (any non-null DreamResult counts). Pending
Vineeth confirmation — will adjust to strict/middle if requested.

Tests pending in follow-up commits.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/deriver/enqueue.py

@@ -1,5 +1,4 @@
 import logging
-from datetime import datetime, timezone
 from typing import Any, Literal
 
 from sqlalchemy import exists, insert, select
@@ -516,8 +515,8 @@ async def enqueue_dream(
             stmt = insert(QueueItem).returning(QueueItem)
             await db_session.execute(stmt, [dream_record])
 
-            # Update collection metadata (CRUD handles cache invalidation)
-            now_iso = datetime.now(timezone.utc).isoformat()
+            # Update collection metadata (CRUD handles cache invalidation).
+            # last_dream_at is written at completion in process_dream, not here.
             await crud.update_collection_internal_metadata(
                 db_session,
                 workspace_name,
@@ -526,7 +525,6 @@ async def enqueue_dream(
                 update_data={
                     "dream": {
                         "last_dream_document_count": document_count,
-                        "last_dream_at": now_iso,
                     }
                 },
             )

src/dreamer/dream_scheduler.py

@@ -254,11 +254,13 @@ async def check_and_schedule_dream(
     last_dream_document_count = dream_metadata.get("last_dream_document_count", 0)
     last_dream_at = dream_metadata.get("last_dream_at")
 
-    # Count current documents in the collection
+    # Count explicit-level docs only: dreamer output (deductive/inductive/
+    # contradiction) would inflate the threshold and create a feedback loop.
     count_stmt = select(func.count(models.Document.id)).where(
         models.Document.workspace_name == collection.workspace_name,
         models.Document.observer == collection.observer,
         models.Document.observed == collection.observed,
+        models.Document.level == "explicit",
     )
     current_document_count = int(await db.scalar(count_stmt) or 0)
 

src/dreamer/orchestrator.py

@@ -17,6 +17,7 @@ import logging
 import time
 import uuid
 from dataclasses import dataclass
+from datetime import datetime, timezone
 from typing import Any
 
 import sentry_sdk
@@ -323,6 +324,18 @@ DREAM: {payload.dream_type} documents for {workspace_name}/{payload.observer}/{p
                         + f"duration={result.total_duration_ms:.0f}ms"
                     )
 
+                    # Write last_dream_at at completion (not enqueue) so duplicate
+                    # enqueues can't reset the 8h guard. Lenient: any non-null result.
+                    now_iso = datetime.now(timezone.utc).isoformat()
+                    async with tracked_db("dream.last_dream_at_write") as db:
+                        await crud.update_collection_internal_metadata(
+                            db,
+                            workspace_name,
+                            payload.observer,
+                            payload.observed,
+                            update_data={"dream": {"last_dream_at": now_iso}},
+                        )
+
     except Exception as e:
         logger.error(
             f"Error processing dream task {payload.dream_type} for {payload.observer}/{payload.observed}: {str(e)}",