Generated configs out of the repo: *.example.* templates only; configure.py refuses to apply over CHANGEME placeholders

A deploy copied mediamtx.yml (template) over the server's generated file and the next apply
wiped all streamers. Generated files are now gitignored so scp -r cannot clobber them.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

README.md

@@ -35,6 +35,12 @@ works from ~/vanguard-stream without sudo.
 
 ## 3. Configure (domain, admin, streamers, editors)
 
+> `mediamtx.yml`, `copyparty.conf`, `Caddyfile`, `dump-users.txt` and `.env` are **generated on the server**
+> by `configure.py` and gitignored. The `*.example.*` files in the repo are reference only. **Never copy them
+> to the server**: doing so once replaced the live streamer passwords with `CHANGEME` and the next apply
+> wiped the streamers. To update the server, copy scripts (`configure.py`, `bin/`, `docker-compose.yml`, …)
+> and re-run `./configure.py`.
+
     cd ~/vanguard-stream
     ./configure.py --full      # first time: asks everything, then applies
     ./configure.py             # later: add/remove/reset streamers and editors, then apply