feat: v3.0.0 architecture overhaul

- Rename marketplace to lm-claude-plugins
- Move MCP servers to root with symlinks
- Add 6 PR tools to Gitea MCP (list_pull_requests, get_pull_request,
  get_pr_diff, get_pr_comments, create_pr_review, add_pr_comment)
- Add clarity-assist plugin (prompt optimization with ND accommodations)
- Add git-flow plugin (workflow automation)
- Add pr-review plugin (multi-agent review with confidence scoring)
- Centralize configuration docs
- Update all documentation for v3.0.0

BREAKING CHANGE: MCP server paths changed, marketplace renamed

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

plugins/git-flow/commands/branch-cleanup.md

@@ -0,0 +1,94 @@
+# /branch-cleanup - Clean Merged Branches
+
+## Purpose
+
+Remove branches that have been merged, both locally and optionally on remote.
+
+## Behavior
+
+### Step 1: Identify Merged Branches
+
+```bash
+# Find merged local branches
+git branch --merged <base-branch>
+
+# Find merged remote branches
+git branch -r --merged <base-branch>
+```
+
+### Step 2: Present Findings
+
+```
+Found 5 merged branches:
+
+Local:
+  - feat/login-page (merged 3 days ago)
+  - fix/typo-header (merged 1 week ago)
+  - chore/deps-update (merged 2 weeks ago)
+
+Remote:
+  - origin/feat/login-page
+  - origin/fix/typo-header
+
+Protected (won't delete):
+  - main
+  - development
+  - staging
+
+Delete these branches?
+1. Delete all (local + remote)
+2. Delete local only
+3. Let me pick which ones
+4. Cancel
+```
+
+### Step 3: Execute Cleanup
+
+```bash
+# Delete local
+git branch -d <branch-name>
+
+# Delete remote
+git push origin --delete <branch-name>
+```
+
+### Step 4: Report
+
+```
+Cleanup complete:
+
+Deleted local: 3 branches
+Deleted remote: 2 branches
+Skipped: 0 branches
+
+Remaining local branches:
+  - main
+  - development
+  - feat/current-work (not merged)
+```
+
+## Environment Variables
+
+| Variable | Default | Description |
+|----------|---------|-------------|
+| `GIT_DEFAULT_BASE` | `development` | Base branch for merge detection |
+| `GIT_PROTECTED_BRANCHES` | `main,master,development,staging,production` | Never delete these |
+| `GIT_AUTO_DELETE_REMOTE` | `false` | Auto-delete remote branches |
+
+## Safety
+
+- Never deletes protected branches
+- Warns about unmerged branches
+- Confirms before deleting remote branches
+- Uses `-d` (safe delete) not `-D` (force delete)
+
+## Output
+
+On success:
+```
+Cleaned up:
+  Local: 3 branches deleted
+  Remote: 2 branches deleted
+
+Repository is tidy!
+```