fix(orchestrator): default code tasks route to dev, not cell_pm

_classify_code_task routed every default-complexity (medium) code task to cell_pm even when the description named no coordination work. The PM then re-delegated back to a developer, adding a useless hop and producing the smoke-test pattern where main_pm/cell_pm tried to do every lifecycle stage themselves.

Drop the complexity==medium → cell_pm branch. Cell PM now lights up only when the description carries an actual coordination keyword (coordinate, integration, cross-team, sync, planning, milestone, dependencies, review). High/critical complexity, cross-cell keywords, missing team, and team=all still route to main_pm. Adds 11 unit tests; full suite 363 passing.

Surfaced live during NAS smoke.

roboco/runtime/orchestrator.py

@@ -3239,7 +3239,13 @@ Start by:
         return None
 
     def _classify_code_task(self, task: dict[str, Any]) -> str:
-        """Classify a generic `code` task via keyword/complexity heuristics."""
+        """Classify a generic `code` task via keyword/complexity heuristics.
+
+        Default for a single-team code task is `dev` — implementation tasks
+        belong to developers. Cell PM intermediation is reserved for tasks
+        that explicitly signal coordination work (PM keywords) so the PM
+        does not become a re-delegation hop on every routine ticket.
+        """
         team = task.get("team")
         title = (task.get("title") or "").lower()
         description = (task.get("description") or "").lower()
@@ -3257,7 +3263,11 @@ Start by:
         ):
             return "main_pm"
 
-        if self._has_pm_keywords(text) or complexity == "medium":
+        # Cell PM only for tasks that name actual coordination work
+        # (coordinate, integration, cross-team, sync, planning, milestone,
+        # dependencies, review). Plain "medium-complexity" no longer
+        # triggers PM routing — the PM was just a re-delegation hop.
+        if self._has_pm_keywords(text):
             return "cell_pm"
 
         return "dev"

tests/unit/runtime/test_orchestrator_dispatch_classifier.py

@@ -0,0 +1,106 @@
+"""Tests for the orchestrator's task-routing classifier.
+
+Phase 4 follow-up: prevent default code/medium tasks from being routed to
+the Cell PM as a re-delegation hop. Single-team code work belongs to a
+developer unless the description explicitly names coordination work.
+"""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+import pytest
+from roboco.runtime.orchestrator import AgentOrchestrator
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+
+@pytest.fixture
+def orch(tmp_path: Path) -> AgentOrchestrator:
+    """Bare orchestrator instance for classifier-only tests."""
+    return AgentOrchestrator(
+        blueprints_dir=tmp_path / "blueprints",
+        mcp_config_dir=tmp_path / ".mcp",
+        project_root=tmp_path,
+    )
+
+
+def _task(**overrides: object) -> dict[str, object]:
+    base: dict[str, object] = {
+        "title": "Add login endpoint",
+        "description": "Implement POST /login that issues a session token.",
+        "task_type": "code",
+        "team": "backend",
+        "estimated_complexity": "medium",
+    }
+    base.update(overrides)
+    return base
+
+
+class TestCodeTaskDefaultsToDev:
+    def test_medium_complexity_no_pm_keywords_routes_to_dev(
+        self, orch: AgentOrchestrator
+    ) -> None:
+        """Default for a code/medium/single-team task is dev, not cell_pm."""
+        task = _task()
+        assert orch._classify_task_routing(task) == "dev"
+
+    def test_low_complexity_routes_to_dev(self, orch: AgentOrchestrator) -> None:
+        task = _task(estimated_complexity="low")
+        assert orch._classify_task_routing(task) == "dev"
+
+
+class TestComplexityRouting:
+    def test_high_complexity_routes_to_main_pm(self, orch: AgentOrchestrator) -> None:
+        task = _task(estimated_complexity="high")
+        assert orch._classify_task_routing(task) == "main_pm"
+
+    def test_critical_complexity_routes_to_main_pm(
+        self, orch: AgentOrchestrator
+    ) -> None:
+        task = _task(estimated_complexity="critical")
+        assert orch._classify_task_routing(task) == "main_pm"
+
+
+class TestKeywordRouting:
+    def test_pm_keyword_in_description_routes_to_cell_pm(
+        self, orch: AgentOrchestrator
+    ) -> None:
+        """Cell PM lights up only when the task names actual coordination."""
+        task = _task(description="Coordinate the rollout with the API team.")
+        assert orch._classify_task_routing(task) == "cell_pm"
+
+    def test_cross_cell_keyword_routes_to_main_pm(
+        self, orch: AgentOrchestrator
+    ) -> None:
+        task = _task(description="Backend and frontend changes for SSO.")
+        assert orch._classify_task_routing(task) == "main_pm"
+
+    def test_board_keyword_routes_to_board(self, orch: AgentOrchestrator) -> None:
+        task = _task(description="Update product roadmap for the next quarter.")
+        assert orch._classify_task_routing(task) == "board"
+
+
+class TestTeamlessRouting:
+    def test_no_team_routes_to_main_pm(self, orch: AgentOrchestrator) -> None:
+        task = _task(team=None)
+        assert orch._classify_task_routing(task) == "main_pm"
+
+    def test_team_all_routes_to_main_pm(self, orch: AgentOrchestrator) -> None:
+        task = _task(team="all")
+        assert orch._classify_task_routing(task) == "main_pm"
+
+
+class TestNonCodeTaskTypes:
+    def test_planning_routes_to_cell_pm_when_team_is_cell(
+        self, orch: AgentOrchestrator
+    ) -> None:
+        task = _task(task_type="planning")
+        assert orch._classify_task_routing(task) == "cell_pm"
+
+    def test_planning_routes_to_main_pm_when_no_cell(
+        self, orch: AgentOrchestrator
+    ) -> None:
+        task = _task(task_type="planning", team="board")
+        assert orch._classify_task_routing(task) == "main_pm"