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/config/test_env_interpolation.py

@@ -82,38 +82,37 @@ class TestResolveConfig:
         assert saved["channels"]["telegram"]["token"] == "${MY_TOKEN}"
 
     def test_preserves_excluded_fields_when_no_env_refs(self, tmp_path):
-        """Regression: fields with ``exclude=True`` (e.g. DreamConfig.cron)
+        """Regression: fields with ``exclude=True`` (e.g. ProviderConfig.openai_codex)
         must survive ``resolve_config_env_vars`` when the config has no
         ``${VAR}`` references. Previously the unconditional dump→revalidate
         roundtrip silently dropped them."""
         config_path = tmp_path / "config.json"
         config_path.write_text(
             json.dumps(
-                {"agents": {"defaults": {"dream": {"cron": "5 11 * * *"}}}}
+                {"providers": {"openaiCodex": {"apiKey": "secret"}}}
             ),
             encoding="utf-8",
         )
 
         raw = load_config(config_path)
-        assert raw.agents.defaults.dream.cron == "5 11 * * *"
+        assert raw.providers.openai_codex.api_key == "secret"
 
         resolved = resolve_config_env_vars(raw)
-        assert resolved.agents.defaults.dream.cron == "5 11 * * *"
-        assert resolved.agents.defaults.dream.describe_schedule() == (
-            "cron 5 11 * * * (legacy)"
-        )
+        assert resolved.providers.openai_codex.api_key == "secret"
 
     def test_preserves_excluded_fields_with_env_refs(self, tmp_path, monkeypatch):
         """Excluded fields must also survive when the config contains
-        ``${VAR}`` refs elsewhere. An in-place walk preserves the legacy
-        ``cron`` override even as unrelated string fields are substituted."""
+        ``${VAR}`` refs elsewhere. An in-place walk preserves the excluded
+        field even as unrelated string fields are substituted."""
         monkeypatch.setenv("TEST_API_KEY", "resolved-key")
         config_path = tmp_path / "config.json"
         config_path.write_text(
             json.dumps(
                 {
-                    "agents": {"defaults": {"dream": {"cron": "5 11 * * *"}}},
-                    "providers": {"groq": {"apiKey": "${TEST_API_KEY}"}},
+                    "providers": {
+                        "openaiCodex": {"apiKey": "secret"},
+                        "groq": {"apiKey": "${TEST_API_KEY}"},
+                    }
                 }
             ),
             encoding="utf-8",
@@ -123,7 +122,4 @@ class TestResolveConfig:
         resolved = resolve_config_env_vars(raw)
 
         assert resolved.providers.groq.api_key == "resolved-key"
-        assert resolved.agents.defaults.dream.cron == "5 11 * * *"
-        assert resolved.agents.defaults.dream.describe_schedule() == (
-            "cron 5 11 * * * (legacy)"
-        )
+        assert resolved.providers.openai_codex.api_key == "secret"