Merge commit 'refs/phase3/pre-ajax/publication-tip' into integration/pre-ajax-release

# Conflicts:
#	routes/chat_routes.py
#	routes/session_routes.py
#	src/agent_loop.py
#	src/agent_tools/filesystem_tools.py
#	src/teacher_escalation.py
#	src/tool_capabilities.py
#	src/tool_execution.py
#	tests/test_mcp_add_server_args_validation.py
#	tests/test_token_cache_atomic_swap.py

tests/test_teacher_eval_tier2.py

@@ -3,9 +3,15 @@ import json
 from types import SimpleNamespace
 import pytest
 
+import src.tool_capabilities as tool_capabilities
 import src.teacher_escalation as teacher_escalation
 
 
+@pytest.fixture(autouse=True)
+def _enable_approval_gate_for_legacy_gate_tests(monkeypatch):
+    monkeypatch.setattr(tool_capabilities, "TOOL_APPROVAL_GATE_ENABLED", True)
+
+
 @pytest.mark.asyncio
 async def test_evaluate_turn_llm_ok(monkeypatch):
     seen = {}