test(coverage): add Behave BDD tests to improve unit test coverage across 53 source modules

Add 53 new .feature files and corresponding step definition files targeting
uncovered lines identified in build/coverage.xml. Fix AmbiguousStep conflicts
in 7 pre-existing step files by disambiguating step text.

New tests cover: ACP clients/facade, actor CLI/config, application container,
ACMS service/strategies, async worker, automation profile CLI, autonomy
guardrail, bridge, change model, config CLI/service, context service,
cross-plan correction, database models, decision service, decomposition
clustering/service, discovery handler, langchain chat provider, langgraph
nodes, materializers, multi-project service, plan apply/CLI/lifecycle/model/
preflight/resume/service, PostgreSQL analyzer, project CLI/context CLI,
provider registry, reactive application/route, repositories, resolver handler,
resource registry service, resume model, retry patterns, sandbox protocol,
server CLI, skill CLI/service, skills registry, subplan execution/service,
system CLI, UKO loader, UoW, and YAML template engine.

Closes #645

features/bridge_coverage_boost.feature

@@ -0,0 +1,41 @@
+Feature: Bridge coverage boost for uncovered lines in bridge.py
+  As a developer
+  I want thorough tests for remaining uncovered lines in bridge.py
+  So that code coverage reaches its maximum
+
+  # Targets uncovered lines:
+  #   Line 64:  early return from cleanup_tasks_async when no tasks exist
+  #   Lines 79-83: pending tasks that do not complete within timeout
+  #   Lines 89-93: late tasks added to _active_tasks during cleanup await
+  #   Line 149: MESSAGE_ROUTER node with "rules" in create_graph_from_config
+  #   Lines 282-290: execute_node inner coroutine in _create_node_operator
+
+  Scenario: cleanup_tasks_async returns immediately when no tasks are active
+    Given a bridge with an empty active tasks set
+    When I call cleanup_tasks_async on the idle bridge
+    Then the async cleanup should complete without error
+    And the bridge active task set should remain empty
+
+  Scenario: cleanup_tasks_async logs pending tasks that exceed timeout
+    Given a bridge with a task that ignores cancellation
+    When I call cleanup_tasks_async with a very short timeout
+    Then pending tasks should be re-cancelled after the timeout
+    And the bridge active task set should be cleared after timeout cleanup
+
+  Scenario: cleanup_tasks_async cancels late tasks added during await
+    Given a bridge with a task whose done-callback spawns a late task
+    When I call cleanup_tasks_async allowing callback to fire
+    Then the late task should be cancelled during cleanup
+    And the bridge active task set should be cleared after late-task cleanup
+
+  Scenario: create_graph_from_config sets rules metadata for MESSAGE_ROUTER nodes
+    Given a bridge ready to create graphs from config
+    When I create a graph with a MESSAGE_ROUTER node containing rules
+    Then the node config metadata should contain the routing rules
+
+  Scenario: Node operator executes the inner coroutine and updates state
+    Given a bridge with a graph containing a mock executable node
+    When I pipe a message through the node operator and await the result
+    Then the node execute method should have been called
+    And the state manager should have been updated with the node result
+    And the returned message metadata should contain the node and graph names