feat(orchestrator): wire GoalDecomposer into bot_flow.py

Replace the old dual-path orchestrator (abstract goals vs legacy desires)
with unified GoalDecomposer-driven task routing:

1. GoalDecomposer reads mission.strategy + plugins config
2. Generates weighted Task objects (verb, target_screen, budget)
3. GrowthBrain.select_task() picks one probabilistically
4. Selected Task's target_screen routes through existing nav_graph
5. Feed loops + PluginRegistry handle the actual interactions

The abstract goals path (goal_executor.achieve('Nurture community'))
that caused infinite scrolling is now eliminated entirely.

Legacy desire fallback preserved for configs without plugins.

22/22 tests passing.

tests/tdd/test_goal_decomposer.py

@@ -317,3 +317,86 @@ class TestGrowthBrainTaskSelection:
 
         # With aggressive_growth, ExploreFeed (weight 0.45) should dominate
         assert len(counts) > 1, "Selection must pick from multiple screens"
+
+
+class TestOrchestratorTaskRouting:
+    """Tests that every Task produced by GoalDecomposer is routable by ScreenTopology."""
+
+    def test_task_to_screen_topology_mapping(self):
+        """Each Task.target_screen MUST exist in ScreenTopology.SCREEN_NAME_MAP."""
+        from GramAddict.core.goal_decomposer import GoalDecomposer
+        from GramAddict.core.screen_topology import ScreenTopology
+
+        plugins = {
+            "likes": {"percentage": 100},
+            "follow": {"percentage": 100},
+            "comment": {"percentage": 40},
+            "story_view": {"percentage": 80},
+            "dm_reply": {"enabled": True},
+        }
+        actions = {"feed": "5-10", "explore": "5-10", "reels": "3-5"}
+        mission = {"strategy": "aggressive_growth"}
+
+        decomposer = GoalDecomposer(plugins=plugins, actions=actions, mission=mission)
+        tasks = decomposer.generate_tasks()
+
+        assert len(tasks) > 0
+
+        for task in tasks:
+            assert task.target_screen in ScreenTopology.SCREEN_NAME_MAP, (
+                f"Task '{task.verb}' → '{task.target_screen}' has no ScreenTopology mapping!"
+            )
+
+    def test_all_task_screens_reachable_from_home(self):
+        """Every Task target must be reachable via BFS from HOME_FEED."""
+        from GramAddict.core.goal_decomposer import GoalDecomposer
+        from GramAddict.core.screen_topology import ScreenTopology
+        from GramAddict.core.perception.screen_identity import ScreenType
+
+        plugins = {
+            "likes": {"percentage": 100},
+            "story_view": {"percentage": 80},
+            "dm_reply": {"enabled": True},
+        }
+        actions = {"feed": "5-10", "explore": "5-10"}
+        mission = {"strategy": "community_builder"}
+
+        decomposer = GoalDecomposer(plugins=plugins, actions=actions, mission=mission)
+        tasks = decomposer.generate_tasks()
+
+        for task in tasks:
+            target_type = ScreenTopology.SCREEN_NAME_MAP.get(task.target_screen)
+            assert target_type is not None
+
+            if target_type == ScreenType.HOME_FEED:
+                continue  # Already there
+
+            route = ScreenTopology.find_route(ScreenType.HOME_FEED, target_type)
+            assert route is not None, (
+                f"No HD Map route from HOME_FEED to {task.target_screen}! "
+                f"The bot cannot navigate there."
+            )
+
+    def test_task_target_screen_to_goal_string_conversion(self):
+        """Every task target_screen must convert to a valid GOAP goal string."""
+        from GramAddict.core.goal_decomposer import GoalDecomposer
+        from GramAddict.core.screen_topology import ScreenTopology
+
+        plugins = {"likes": {"percentage": 100}, "dm_reply": {"enabled": True}}
+        actions = {"feed": "5-10", "explore": "5-10"}
+        mission = {"strategy": "aggressive_growth"}
+
+        decomposer = GoalDecomposer(plugins=plugins, actions=actions, mission=mission)
+        tasks = decomposer.generate_tasks()
+
+        for task in tasks:
+            goal_str = ScreenTopology.screen_name_to_goal(task.target_screen)
+            assert goal_str, (
+                f"Task '{task.target_screen}' cannot be converted to GOAP goal!"
+            )
+            # The goal string should resolve back to a target screen
+            target = ScreenTopology.goal_to_target_screen(goal_str)
+            assert target is not None, (
+                f"Goal string '{goal_str}' doesn't resolve to any ScreenType!"
+            )
+