feat: add proxy template origin field and implement socket utilities for log streaming

backend/tests/api/test_proxy.py

@@ -9,7 +9,7 @@ from app.core.security import get_auth_context, require_authenticated_user
 from app.models.health import HealthSnapshot
 from app.models.proxy import ProxyCreateInput, ProxyDocument
 from app.models.service import ServiceEndpointDocument
-from app.services.mitmproxy.templates import BUILTIN_TEMPLATES
+from app.services.mitmproxy.templates import list_file_templates
 from app.services.mitmproxy.validator import ProxyCodeValidationError
 
 proxy_router_module = importlib.import_module("app.api.proxy.router")
@@ -864,6 +864,8 @@ def test_stop_proxy_updates_runtime_state(client, monkeypatch: object):
 
 
 def test_list_mitmproxy_templates_returns_builtins_and_custom(client, monkeypatch):
+    file_templates = list_file_templates()
+
     async def fake_list_custom_templates():
         return []
 
@@ -872,13 +874,19 @@ def test_list_mitmproxy_templates_returns_builtins_and_custom(client, monkeypatc
         "list_custom_templates",
         fake_list_custom_templates,
     )
+    monkeypatch.setattr(
+        proxy_router_module,
+        "list_file_templates",
+        lambda: file_templates,
+    )
 
     response = client.get("/proxy/mitmproxy/templates")
 
     assert response.status_code == 200
     body = response.json()
-    assert len(body) == len(BUILTIN_TEMPLATES)
+    assert len(body) == len(file_templates)
     assert body[0]["built_in"] is True
+    assert body[0]["origin"] == "file"
     assert body[0]["protocol"] in {"http", "tcp"}
     assert isinstance(body[0]["tags"], list)
     assert body[0]["action"] in {"block", "rewrite"}
@@ -906,6 +914,7 @@ def test_create_mitmproxy_template_validates_and_persists(client, monkeypatch):
             "code": payload.code,
             "source_url": payload.source_url,
             "built_in": False,
+            "origin": "custom",
         }
 
     monkeypatch.setattr(
@@ -939,4 +948,33 @@ def test_create_mitmproxy_template_validates_and_persists(client, monkeypatch):
     assert response.status_code == 201
     assert response.json()["id"] == "custom-header"
     assert response.json()["protocol"] == "http"
+    assert response.json()["origin"] == "custom"
     assert captured["validated"] == "def response(flow):\n    pass\n"
+
+
+def test_create_mitmproxy_template_rejects_file_backed_id(client, monkeypatch):
+    monkeypatch.setattr(
+        proxy_router_module,
+        "file_template_ids",
+        lambda: {"http-block-path-traversal"},
+    )
+
+    response = client.post(
+        "/proxy/mitmproxy/templates",
+        json={
+            "id": "http-block-path-traversal",
+            "name": "Custom header",
+            "description": "Adds a custom response header",
+            "category": "http",
+            "protocol": "http",
+            "family": "custom",
+            "tags": [],
+            "action": "custom",
+            "summary": "Saved custom template.",
+            "behavior": "Applies the current script as-is.",
+            "code": "def response(flow):\n    pass\n",
+        },
+    )
+
+    assert response.status_code == 409
+    assert "Template already exists" in response.json()["detail"]