Fix raw action config endpoint shadowed by config router

Rename GET/PUT /api/config/actions/{name} to /actions/{name}/raw in
file_config.py to eliminate the route-shadowing conflict with config.py,
which registers its own GET /actions/{name} returning ActionConfig.

Add configActionRaw endpoint helper in endpoints.ts and update
fetchActionFile/updateActionFile in config.ts to use it. Add
TestGetActionFileRaw and TestUpdateActionFileRaw test classes.

backend/app/routers/file_config.py

@@ -14,8 +14,8 @@ Endpoints:
 * ``GET  /api/config/filters/{name}/parsed``        — parse a filter file into a structured model
 * ``PUT  /api/config/filters/{name}/parsed``        — update a filter file from a structured model
 * ``GET  /api/config/actions``                     — list all action files
-* ``GET  /api/config/actions/{name}``              — get one action file (with content)
-* ``PUT  /api/config/actions/{name}``              — update an action file
+* ``GET  /api/config/actions/{name}/raw``          — get one action file (raw content)
+* ``PUT  /api/config/actions/{name}/raw``          — update an action file (raw content)
 * ``POST /api/config/actions``                     — create a new action file
 * ``GET  /api/config/actions/{name}/parsed``        — parse an action file into a structured model
 * ``PUT  /api/config/actions/{name}/parsed``        — update an action file from a structured model
@@ -460,7 +460,7 @@ async def list_action_files(
 
 
 @router.get(
-    "/actions/{name}",
+    "/actions/{name}/raw",
     response_model=ConfFileContent,
     summary="Return an action definition file with its content",
 )
@@ -496,7 +496,7 @@ async def get_action_file(
 
 
 @router.put(
-    "/actions/{name}",
+    "/actions/{name}/raw",
     status_code=status.HTTP_204_NO_CONTENT,
     summary="Update an action definition file",
 )