chore: remove duplicate web/dev-server.py

The repo had two near-duplicate no-cache dev servers. The root dev-server.py
(serves web/ via directory=, documented in the README) is canonical; web/dev-server.py
was a later re-implementation that served CWD and required 'cd web' first. Keeping
both meant every change had to be written twice and drifted — PR #16 had to paste
--host into both files.

Delete the web/ copy and drop its now-stale .dockerignore entry. No docs or scripts
reference it; the README and Docker path both point at the root server.

.dockerignore

@@ -28,10 +28,9 @@ prototype/stress/models/
 node_modules/
 dist/
 
-# The dev servers and Cloudflare redirect file are not used by the nginx image
+# The dev server and Cloudflare redirect file are not used by the nginx image
 # (redirects are implemented in nginx.conf).
 dev-server.py
-web/dev-server.py
 web/_redirects
 
 # Docs aren't needed at runtime.

web/dev-server.py

@@ -1,67 +0,0 @@
-#!/usr/bin/env python3
-"""
-Dev server for Support Fins -- serves web/ with caching turned OFF.
-
-WHY THIS EXISTS: the app is vanilla ES modules loaded with static imports. Python's
-plain `http.server` sends no Cache-Control header, so Chrome applies HEURISTIC caching
-and will serve a STALE prop.js / fins.js on an ordinary reload -- you edit the engine,
-reload, and see the OLD geometry, with no hint anything is wrong. That has burned us
-repeatedly ("kill the app and restart"). This server sends `Cache-Control: no-store`
-on everything, so every reload fetches the current file. No hard-reload needed.
-
-    cd ~/projects/support-fins/web && python3 dev-server.py        # -> http://localhost:8731
-    python3 dev-server.py 8080                                     # custom port
-    python3 dev-server.py --host 0.0.0.0                           # reach from other devices on the LAN
-"""
-import argparse
-import socket
-import sys
-from http.server import SimpleHTTPRequestHandler, ThreadingHTTPServer
-
-
-class NoCacheHandler(SimpleHTTPRequestHandler):
-    def end_headers(self):
-        self.send_header("Cache-Control", "no-store, no-cache, must-revalidate, max-age=0")
-        self.send_header("Pragma", "no-cache")
-        self.send_header("Expires", "0")
-        super().end_headers()
-
-    def log_message(self, fmt, *args):
-        pass  # quiet
-
-
-def _lan_ip():
-    """Best-effort LAN address for the "reachable at" hint. No packets are sent."""
-    try:
-        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
-        s.connect(("8.8.8.8", 80))  # pick a route; the OS resolves the local end without sending
-        ip = s.getsockname()[0]
-        s.close()
-        return ip
-    except OSError:
-        return None
-
-
-if __name__ == "__main__":
-    parser = argparse.ArgumentParser(
-        description="Support Fins no-cache dev server.",
-        epilog="Bind 0.0.0.0 (or ::) to reach the server from other devices on your LAN.",
-    )
-    parser.add_argument("port", nargs="?", type=int, default=8731,
-                        help="port to listen on (default: 8731)")
-    parser.add_argument("--host", default="127.0.0.1",
-                        help="address to bind (default: 127.0.0.1; 0.0.0.0 exposes it to the LAN)")
-    args = parser.parse_args()
-
-    # Serves the current working directory -- run it from inside web/:
-    #   cd ~/projects/support-fins/web && python3 dev-server.py
-    wildcard = args.host in ("0.0.0.0", "::", "")
-    bind = "" if wildcard else args.host
-    print(f"Support Fins dev server (no-cache) -> http://localhost:{args.port}")
-    if wildcard:
-        ip = _lan_ip()
-        if ip:
-            print(f"On other devices on your LAN, open http://{ip}:{args.port}")
-    print("Every reload fetches fresh JS -- no hard-reload needed. Ctrl-C to stop.")
-    sys.stdout.flush()  # ensure the lines above land in a redirected log immediately (e.g. headless RPi)
-    ThreadingHTTPServer((bind, args.port), NoCacheHandler).serve_forever()