fix(asgi): redirect /mcp → /mcp/ for clients that omit the trailing slash

Starlette's Mount("/mcp", ...) only matches /mcp/* paths. A POST to bare
/mcp falls through to the catch-all Django mount and returns 404. The
fast-agent MCP client and the README example both used the no-slash URL,
so the validator was never able to initialize a session — every call
landed in django.request.

Adds a 307 redirect at /mcp so any client URL works, and points the
validator config at /mcp/ directly to skip the redirect round-trip.
Also gitignores fastagent.jsonl (a runtime log file fast-agent writes
into the working directory).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

validator/.gitignore

@@ -1,4 +1,5 @@
 fastagent.secrets.yaml
+fastagent.jsonl
 .venv/
 *.egg-info/
 __pycache__/

validator/README.md

@@ -55,7 +55,7 @@ cd mnemosyne/
 uvicorn mnemosyne.asgi:app --host 0.0.0.0 --port 22091 --workers 1
 ```
 
-By default the validator points at `http://localhost:22091/mcp`. If your Mnemosyne is on another host, override `mcp.servers.mnemosyne.url` in `fastagent.secrets.yaml`.
+By default the validator points at `http://localhost:22091/mcp/` (note the trailing slash — Starlette's `Mount` only matches paths under the mount prefix, so `/mcp` without the slash falls through to Django). If your Mnemosyne is on another host, override `mcp.servers.mnemosyne.url` in `fastagent.secrets.yaml`.
 
 ## Run the validator
 

validator/fastagent.config.yaml

@@ -27,6 +27,6 @@ mcp:
     # override the URL in fastagent.secrets.yaml or via Ansible if remote.
     mnemosyne:
       transport: http
-      url: "http://localhost:22091/mcp"
+      url: "http://localhost:22091/mcp/"
       # Bearer token in fastagent.secrets.yaml (provisioned via
       # `python manage.py create_mcp_token <user>`).