docs: Add branch-per-feature + Gitea MR workflow to CLAUDE.md

Feature work now goes on feat/<slug> branches; Claude pushes and prints
the Gitea compare URL for the user to open the MR. Exceptions documented
for small fixes and typo tweaks.

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

CLAUDE.md

@@ -92,6 +92,34 @@ Tiers are set in column B of the attendance sheet:
 
 `/qr?account=…&amount=…&message=…` generates a Czech QR Platba PNG (SPD format).
 
+## Branching & merge requests
+
+The remote is Gitea (`gitea.home.hrajfrisbee.cz/kacerr/fuj-management`).
+For **features**, do not commit to `main` directly. Use a branch + merge
+request flow:
+
+1. **Create a branch off `main`** before starting work:
+   - `feat/<slug>` for features (e.g. `feat/qr-code-overlay`)
+   - `fix/<slug>` for bug-fix branches the user explicitly asks for
+   - `<slug>` is short kebab-case
+2. **Commit on the branch** following the existing commit conventions
+   (Co-Authored-By trailer, etc.).
+3. **Push the branch** to `origin` with `-u` so it tracks.
+4. **Print the Gitea compare URL** so the user can open the MR in the browser:
+   `https://gitea.home.hrajfrisbee.cz/kacerr/fuj-management/compare/main...<branch>`
+   Do **not** use `tea`, `gh`, or call the Gitea API — the user opens and
+   merges the MR themselves.
+5. **Do not merge or delete the branch** from the CLI. The user does that
+   in Gitea.
+
+**Exceptions — when committing straight to `main` is fine:**
+- Small bug fixes / hotfixes the user describes as such.
+- Typo / comment / formatting tweaks.
+- Edits the user explicitly says to push to `main`.
+
+When uncertain whether something is a feature or a small fix, ask before
+committing.
+
 ## Git Commits
 
 When making git commits, always append yourself as co-author trailer to the end of the commit message to indicate AI assistance