Security: feedback/inbox.jsonl and feedback/lastseen.json are HTTP-readable

[companygardener]

Summary

lib/server.py serves the entire artifact directory via SimpleHTTPRequestHandler, including the feedback/ subdirectory. The in-page library only needs feedback/history.json (which it polls to detect new walkthroughs); inbox.jsonl (full comment stream) and lastseen.json (per-session bookkeeping) are agent-side state that browser/HTTP clients should not be able to read.

Today, GET /feedback/inbox.jsonl returns the entire comment history with 200 OK.

Impact

• Combined with Security: dev server binds to all interfaces by default (LAN exposure) #2 (server binds to all interfaces), any LAN client can pull the comment stream.
• Even on localhost, this widens the surface that other local processes / browser tabs can see.

Suggested fix

In do_GET, block any path under /feedback/ except history.json. Important: normalize the path first (posixpath.normpath(unquote(path))) so the check isn't bypassed by:

• Dot segments: /./feedback/inbox.jsonl, /x/../feedback/inbox.jsonl
• Double slashes: /feedback//inbox.jsonl
• Percent-encoding: /%66eedback/inbox.jsonl

All four of these resolve to the same file in SimpleHTTPRequestHandler.translate_path, but a naive exact-string check on the raw URL path would let them through.