Serve practice mode from the main server, add mode switch, fix touch

Practice mode is now at /practice on server.py instead of a separate
server, with a button in the bottom-right corner of each page to the
other mode. Touch: no double-tap zoom, no sticky hover after a tap, no
long-press selection on the board, and a pressed look on tapped squares.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

README.md

@@ -12,18 +12,20 @@ python3 -m venv .venv
 .venv/bin/pip install -r requirements.txt
 .venv/bin/python server.py            # http://127.0.0.1:8080
 .venv/bin/python server.py --host 0.0.0.0 --port 8080   # reachable on your LAN
-.venv/bin/python practice.py          # vs the computer: http://127.0.0.1:8081
 ```
 
+Practice mode (vs the computer) is at `/practice` on the same server. The switch in the
+bottom-right corner of each page goes between the two modes.
+
 Tests: `.venv/bin/python -m unittest discover -s tests -t .`
 
 ## How it works
 
 - `game.py`: the rules, no networking.
-- `server.py`: one aiohttp process. `/ws?game=CODE` is the live connection, and
-  everything else is static files.
-- `practice.py`: a separate server for playing against the computer. It holds no state:
-  the page sends the position to `POST /api/play` and gets the next one back.
+- `server.py`: one aiohttp process. `/ws?game=CODE` is the live connection, `/practice`
+  and `POST /api/play` are practice mode, and everything else is static files.
+- `practice.py`: practice mode's move endpoint, mounted by `server.py`. It holds no
+  state: the page sends the position to `POST /api/play` and gets the next one back.
 - `solver.py`: solves every reachable position (~67k, about a second at startup) so the
   computer knows the perfect move everywhere.
 - `static/`: the pages. Plain HTML/CSS/JS, no build step. `board.js` is the board
@@ -66,7 +68,6 @@ your home IP. WebSockets work through it without any extra configuration.
    cloudflared tunnel login
    cloudflared tunnel create moonchess
    cloudflared tunnel route dns moonchess moonchess.example.com
-   cloudflared tunnel route dns moonchess practice.moonchess.example.com   # if running practice.py
    ```
 3. `~/.cloudflared/config.yml`:
    ```yaml
@@ -75,8 +76,6 @@ your home IP. WebSockets work through it without any extra configuration.
    ingress:
      - hostname: moonchess.example.com
        service: http://localhost:8080
-     - hostname: practice.moonchess.example.com   # optional, if you run practice.py
-       service: http://localhost:8081
      - service: http_status:404
    ```
 4. `cloudflared tunnel run moonchess` (or `sudo cloudflared service install` to run it at boot).