feat: pin sessions to workspace revisions

harness/tht/session/models.py

@@ -117,6 +117,8 @@ class SessionManifest(_YamlModel):
     provider: str | None = None
     model: str | None = None
     thinking: str | None = None
+    workspace_id: str | None = None
+    workspace_revision: str | None = None
     name: str | None = None
     archived: bool = False
     group: str | None = None

harness/tht/session/store.py

@@ -102,7 +102,8 @@ def create_session(
     question: str, db: DatabaseConfig, sessions_root: Path,
     *, author: str | None = None, summary: str | None = None,
     provider: str | None = None, model: str | None = None,
-    thinking: str | None = None, name: str | None = None,
+    thinking: str | None = None, workspace_id: str | None = None,
+    workspace_revision: str | None = None, name: str | None = None,
 ) -> SessionManifest:
     now = datetime.now(UTC)
     # stamp con ora/min/sec: identifica univocamente sessioni dello stesso giorno
@@ -123,7 +124,8 @@ def create_session(
         database=db.database, schema=db.db_schema,
         author=who, summary=summary or _summarize(question),
         updated_at=now, updated_by=who, schema_version=schema_version,
-        provider=provider, model=model, thinking=thinking, name=name,
+        provider=provider, model=model, thinking=thinking, workspace_id=workspace_id,
+        workspace_revision=workspace_revision, name=name,
     )
     session_dir = sessions_root / session_id
     manifest.to_yaml(session_dir / MANIFEST)
@@ -132,7 +134,8 @@ def create_session(
 
 
 def new_session_manifest(
-    question: str, db: DatabaseConfig, *, provider=None, model=None, thinking=None, name=None
+    question: str, db: DatabaseConfig, *, provider=None, model=None, thinking=None,
+    workspace_id=None, workspace_revision=None, name=None,
 ) -> SessionManifest:
     """Create an unsaved UUIDv4 manifest for a repository-owned session."""
     now = datetime.now(UTC)
@@ -140,7 +143,8 @@ def new_session_manifest(
         id=str(uuid.uuid4()), created_at=now, question=question,
         database=db.database, schema=db.db_schema, author=current_author(),
         summary=_summarize(question), updated_at=now, updated_by=current_author(),
-        provider=provider, model=model, thinking=thinking, name=name,
+        provider=provider, model=model, thinking=thinking, workspace_id=workspace_id,
+        workspace_revision=workspace_revision, name=name,
     )