refactor(dream): replace two-phase Dream class with simple cron + process_direct (#3990)

* refactor(dream): replace two-phase Dream class with simple cron + process_direct

- Remove the heavyweight Dream class (AgentRunner-based two-phase system)
  from nanobot/agent/memory.py
- Delete dream_phase1.md and dream_phase2.md templates
- New dream.md template serves as the consolidation prompt
- Cron callback uses agent.process_direct(prompt, session_key=\"dream\")
  instead of agent.dream.run()
- Always performs git auto_commit after execution
- /dream command updated to use process_direct + git commit
- DreamConfig kept for backward compatibility; deprecated fields
  (model_override, max_batch_size, max_iterations, annotate_line_ages)
  are ignored but accepted in config
- interval_h remains configurable via agents.defaults.dream.interval_h
- Update tests and webui settings to match new architecture

* feat(loop): add ephemeral mode to process_direct, skip history writes for Dream

When ephemeral=True, _state_save skips enforce_file_cap (which calls
raw_archive -> append_history) and consolidator.maybe_consolidate_by_tokens.
This prevents Dream sessions from creating a positive feedback loop where
they process their own output. The session IS still saved to disk.

* fix(loop): skip extra hooks for ephemeral sessions (Dream)

* feat(dream): per-run timestamped sessions with rotation for WebUI

* test(config): restore DreamConfig schedule and alias tests

* fix(dream): include LLM response summary in git auto-commit message

The old two-phase Dream class included the Phase 1 analysis in the git
commit message body. The new single-phase version lost this. Restore it
by extracting resp.content from the process_direct return value and
appending it to the commit message in both the cron handler and the
/dream command.

* fix(test): accept ephemeral kwarg in test_openai_api fake_process

* refactor(dream): merge dream_session.py into MemoryStore

The standalone dream_session.py module only contained three small helpers
that all revolve around MemoryStore concerns (session keys, commit messages,
file pruning). Fold them into MemoryStore as @staticmethod to reduce
indirection and avoid a 35-line module with no independent reason to exist.

* fix(test): address code review — patch correct instance, use actual function

- Fix test_ephemeral_skips_raw_archive to patch loop.context.memory
  instead of the fixture's separate MemoryStore instance
- Fix TestDreamCommitMessage to call MemoryStore.build_dream_commit_message
  instead of reimplementing the logic inline
- Move Dream helpers in memory.py above the Consolidator section comment
  to avoid misleading visual boundary

* fix(dream): gate cursor advancement and restrict tools

maintainer edit: Dream now processes backlog from the oldest unprocessed entries, only advances the cursor after a completed ephemeral run, and uses a restricted file-only tool registry for background consolidation.

* fix(dream): skip idle compact for dream sessions

Dream runs use internal dream:* sessions that are pruned by Dream retention. Exclude them from AutoCompact scheduling, archive execution, and summary injection so idle-session compaction cannot truncate Dream transcripts.

* fix(dream): keep batched history isolated

* feat(dream): tag archived memory for single-phase Dream

---------

Co-authored-by: Xubin Ren <52506698+Re-bin@users.noreply.github.com>

tests/agent/test_autocompact_unit.py

@@ -203,9 +203,15 @@ class TestCheckExpired:
         old_ts = (datetime.now() - timedelta(minutes=20)).isoformat()
         mock_sm.list_sessions.return_value = [{"key": "cli:old", "updated_at": old_ts}]
         ac.sessions = mock_sm
-        scheduler = MagicMock()
+
+        scheduled = []
+
+        def scheduler(coro):
+            scheduled.append(coro)
+            coro.close()
+
         ac.check_expired(scheduler)
-        scheduler.assert_called_once()
+        assert len(scheduled) == 1
         assert "cli:old" in ac._archiving
 
     def test_active_session_key_skips(self):
@@ -251,6 +257,22 @@ class TestCheckExpired:
         ac.check_expired(scheduler)
         scheduler.assert_not_called()
 
+    def test_dream_session_skips(self):
+        """Internal Dream sessions should not be scheduled for idle compact."""
+        ac = _make_autocompact(ttl=15)
+        mock_sm = MagicMock(spec=SessionManager)
+        old_ts = (datetime.now() - timedelta(minutes=20)).isoformat()
+        mock_sm.list_sessions.return_value = [
+            {"key": "dream:20260602-155256", "updated_at": old_ts},
+        ]
+        ac.sessions = mock_sm
+        scheduler = MagicMock()
+
+        ac.check_expired(scheduler)
+
+        scheduler.assert_not_called()
+        assert "dream:20260602-155256" not in ac._archiving
+
 
 # ---------------------------------------------------------------------------
 # _archive
@@ -273,6 +295,17 @@ class TestArchiveDelegates:
             "cli:test", ac._RECENT_SUFFIX_MESSAGES,
         )
 
+    @pytest.mark.asyncio
+    async def test_dream_session_is_ignored(self):
+        ac = _make_autocompact()
+        ac.consolidator.compact_idle_session = AsyncMock(return_value="Summary.")
+        ac._archiving.add("dream:20260602-155256")
+
+        await ac._archive("dream:20260602-155256")
+
+        ac.consolidator.compact_idle_session.assert_not_awaited()
+        assert "dream:20260602-155256" not in ac._archiving
+
     @pytest.mark.asyncio
     async def test_populates_summaries_from_metadata(self):
         ac = _make_autocompact()
@@ -416,6 +449,33 @@ class TestPrepareSession:
         assert result_session is session
         assert summary is None
 
+    def test_dream_session_skips_reload_and_summaries(self):
+        """Internal Dream sessions should not reload or receive compact summaries."""
+        ac = _make_autocompact(ttl=15)
+        mock_sm = MagicMock(spec=SessionManager)
+        ac.sessions = mock_sm
+        key = "dream:20260602-155256"
+        ac._archiving.add(key)
+        ac._summaries[key] = ("Hot summary.", datetime(2026, 6, 2, 15, 52, 56))
+        session = _make_session(
+            key=key,
+            updated_at=datetime.now() - timedelta(minutes=20),
+            metadata={
+                "_last_summary": {
+                    "text": "Cold summary.",
+                    "last_active": "2026-06-02T15:52:56",
+                },
+            },
+        )
+
+        result_session, summary = ac.prepare_session(session, key)
+
+        mock_sm.get_or_create.assert_not_called()
+        assert result_session is session
+        assert summary is None
+        assert key not in ac._archiving
+        assert key not in ac._summaries
+
     def test_cold_path_metadata_not_dict_returns_none(self):
         """If metadata _last_summary is not a dict, should return None summary."""
         ac = _make_autocompact()