chore: add PR workflow and worktree-aware release process

.claude/commands/pr-create.md

@@ -0,0 +1,12 @@
+Create a PR from the current branch on both GitHub and Gitea.
+
+1. If in a worktree (working directory contains `.claude/worktrees/`), you are already on a feature branch — do NOT create a new one. Otherwise, create a new branch from main with a descriptive name.
+2. Stage and commit all changes with a clean, semantic commit message. No Claude attribution lines.
+3. Fetch latest main: `git fetch origin main`.
+4. Rebase onto main: `git rebase origin/main`.
+   - If conflicts occur, abort the rebase (`git rebase --abort`), analyze the conflicting files, write a plan to resolve them, and present the plan to the user before proceeding.
+5. Push the branch to origin with `-u` (use `--force-with-lease` if the branch was already pushed).
+6. Push the branch to gitea: `git push gitea <branch>`.
+7. Create a GitHub PR: `gh pr create`. Reference related issues with `#X`. Only use `Closes #X` if the PR fully resolves the issue.
+8. Create a Gitea PR: `tea pr create --head <branch> --base main` with the same title and description.
+9. Report both PR URLs.