feat(kanban): add Modal memo evaluator lane

hermes_cli/config.py

@@ -1543,6 +1543,10 @@ def _ensure_hermes_home_managed(home: Path):
         # behaviour — e.g. for a profile that prefers explicit
         # ``kanban_notify-subscribe`` calls per task.
         "auto_subscribe_on_create": True,
+        # Worker execution backend per lane. Only ``memo-evaluator`` supports
+        # ``modal`` in this phase; every other lane remains local even if a
+        # stray config value names Modal.
+        "worker_backends": {"memo-evaluator": "local"},
     },
 
     # Anthropic prompt caching (Claude via OpenRouter or native Anthropic API).

hermes_cli/kanban_db.py

@@ -9739,7 +9739,7 @@ def _dispatch_once_locked(
         if claimed.workspace_kind == "worktree":
             set_branch_name(conn, claimed.id, resolved_branch_name or (claimed.branch_name or "").strip() or f"wt/{claimed.id}")
         _maybe_emit_scratch_tip(conn, claimed.id, claimed.workspace_kind)
-        _spawn = spawn_fn if spawn_fn is not None else _default_spawn
+        _spawn = spawn_fn if spawn_fn is not None else _configured_worker_spawn
         try:
             # Back-compat: older spawn_fn signatures accept only
             # (task, workspace). Test stubs in the suite rely on that.
@@ -10504,6 +10504,20 @@ def _default_spawn(
     return proc.pid
 
 
+def _configured_worker_spawn(
+    task: Task,
+    workspace: str,
+    *,
+    board: Optional[str] = None,
+) -> Optional[int]:
+    """Route the narrowly opted-in Modal lane; retain local spawn otherwise."""
+    from hermes_cli.kanban_modal import resolve_worker_backend, spawn_modal_worker
+
+    if resolve_worker_backend(task.assignee, _load_kanban_cfg()) == "modal":
+        return spawn_modal_worker(task, workspace, board=board)
+    return _default_spawn(task, workspace, board=board)
+
+
 # ---------------------------------------------------------------------------
 # Long-lived dispatcher daemon
 # ---------------------------------------------------------------------------