fix(tests): patch get_engine in _tool_ctx error-path tests

_tool_ctx() calls get_engine() directly rather than accepting a db session,
causing it to bypass the test engine patch from the db fixture. Patch
get_engine to return the test engine before each test and restore after.

Author: prakersh

tests/test_mcp/test_server.py

@@ -70,9 +70,13 @@ def test_tool_ctx_no_access_token(monkeypatch):
             pass
 
 
-def test_tool_ctx_revoked_pat(db, monkeypatch):
+def test_tool_ctx_revoked_pat(db, monkeypatch, engine):
     """_tool_ctx raises ToolError when resolve_token returns None (revoked/expired PAT)."""
-    from fourdpocket.mcp import server
+    import fourdpocket.db.session as db_module
+
+    # Patch get_engine so _tool_ctx() uses the test engine
+    original_get_engine = db_module.get_engine
+    db_module.get_engine = lambda: engine
 
     # Create a valid user
     user_obj = User(
@@ -94,17 +98,25 @@ def fake_get_token():
     def fake_resolve(db_session, token_str):
         return None  # Simulates revoked/expired token
 
+    from fourdpocket.mcp import server as server_module
+
     monkeypatch.setattr("fourdpocket.mcp.server.get_access_token", fake_get_token)
     monkeypatch.setattr("fourdpocket.mcp.server.resolve_token", fake_resolve)
 
-    with pytest.raises(server.tools_mod.ToolError, match="revoked|expired"):
-        with server._tool_ctx():
+    with pytest.raises(server_module.tools_mod.ToolError, match="revoked|expired"):
+        with server_module._tool_ctx():
             pass
 
+    db_module.get_engine = original_get_engine
 
-def test_tool_ctx_inactive_user(db, monkeypatch):
+
+def test_tool_ctx_inactive_user(db, monkeypatch, engine):
     """_tool_ctx raises ToolError when the resolved user is inactive."""
-    from fourdpocket.mcp import server
+    import fourdpocket.db.session as db_module
+    from fourdpocket.mcp import server as server_module
+
+    original_get_engine = db_module.get_engine
+    db_module.get_engine = lambda: engine
 
     # Create an inactive user with a PAT
     inactive_user = User(
@@ -145,14 +157,20 @@ def fake_resolve(db_session, token_str):
     monkeypatch.setattr("fourdpocket.mcp.server.get_access_token", fake_get_token)
     monkeypatch.setattr("fourdpocket.mcp.server.resolve_token", fake_resolve)
 
-    with pytest.raises(server.tools_mod.ToolError, match="disabled"):
-        with server._tool_ctx():
+    with pytest.raises(server_module.tools_mod.ToolError, match="disabled"):
+        with server_module._tool_ctx():
             pass
 
+    db_module.get_engine = original_get_engine
+
 
-def test_tool_ctx_deleted_user(db, monkeypatch):
+def test_tool_ctx_deleted_user(db, monkeypatch, engine):
     """_tool_ctx raises ToolError when the resolved user no longer exists in DB."""
-    from fourdpocket.mcp import server
+    import fourdpocket.db.session as db_module
+    from fourdpocket.mcp import server as server_module
+
+    original_get_engine = db_module.get_engine
+    db_module.get_engine = lambda: engine
 
     # Create a user, then delete them (simulate user_id points to nothing)
     ghost_user = User(
@@ -197,10 +215,12 @@ def fake_resolve(db_session, token_str):
     monkeypatch.setattr("fourdpocket.mcp.server.get_access_token", fake_get_token)
     monkeypatch.setattr("fourdpocket.mcp.server.resolve_token", fake_resolve)
 
-    with pytest.raises(server.tools_mod.ToolError, match="disabled"):
-        with server._tool_ctx():
+    with pytest.raises(server_module.tools_mod.ToolError, match="disabled"):
+        with server_module._tool_ctx():
             pass
 
+    db_module.get_engine = original_get_engine
+
 
 # ─── Tool call wrapper ───────────────────────────────────────────────────────