feat(sync): add install-skills.sh + install metadata to all 62 plugins

- Add install_name, install_type, dir_category fields to all 62 plugin.json files
  to resolve name-mapping and skill-vs-command routing issues
- Add install-skills.sh: idempotent cross-machine skill sync script
  - Routes skill→~/.claude/skills/<name>/, command→~/.claude/commands/<name>.md
  - rsync full skills/ directory (preserves multi-file skills like dev-test, req-deploy)
  - State file ~/.claude/.installed-skills.json tracks installed versions
  - Conflict detection: warns before overwriting locally modified files
  - --dry-run, --category, --force, --cleanup, --list flags
- Add 9 new plugins migrated from local ~/.claude (agent-swarm, ai-chat,
  defect-analysis, executing-plans, finishing-branch, frontend-design,
  req-audit, req-lookback, req-retro)
- Add update-plugin-meta.py helper used to bulk-update plugin.json
- Fix siyuan SKILL.md: remove hardcoded server credentials, use env vars

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

skills-dev/finishing-branch-plugin/skills/SKILL.md

@@ -0,0 +1,104 @@
+---
+name: finishing-a-development-branch
+description: Use when implementation is complete and all tests pass - verifies and creates PR
+---
+
+# Finishing a Development Branch
+
+## Overview
+
+Verify tests pass, then push and create PR.
+
+**Core principle:** Verify tests → Create PR → Done.
+
+**Announce at start:** "I'm using the finishing-a-development-branch skill to complete this work."
+
+## The Process
+
+### Step 1: Verify Tests
+
+**Before creating PR, verify tests pass:**
+
+```bash
+# Run project's test suite
+npm test / cargo test / pytest / go test ./... / mvn test
+```
+
+**If tests fail:**
+```
+Tests failing (<N> failures). Must fix before completing:
+
+[Show failures]
+
+Cannot proceed with PR until tests pass.
+```
+
+Stop. Fix tests first.
+
+**If tests pass:** Continue to Step 2.
+
+### Step 2: Push and Create PR
+
+Use the `/pr create` command which will:
+1. **Check for existing PR first** - avoids duplicates
+2. If PR exists: Report existing PR URL and skip
+3. If no PR: Analyze commits, generate title/description, push, create PR
+
+```bash
+/pr create
+```
+
+**Duplicate prevention:** The `/pr create` command checks for existing open PRs on the current branch before creating a new one.
+
+Report the PR URL when complete (whether existing or newly created).
+
+### Step 3: Cleanup Worktree (if applicable)
+
+Check if working in a worktree:
+```bash
+git worktree list | grep $(git branch --show-current)
+```
+
+If yes, ask user:
+```
+Worktree at <path>. Remove it now? (y/n)
+```
+
+If confirmed:
+```bash
+git worktree remove <worktree-path>
+```
+
+## Quick Reference
+
+```
+Tests Pass?
+    ↓ yes
+/pr create
+    ↓
+PR URL returned
+    ↓
+Cleanup worktree (optional)
+    ↓
+Done
+```
+
+## Red Flags
+
+**Never:**
+- Create PR with failing tests
+- Skip test verification
+- Force-push without explicit request
+
+**Always:**
+- Verify tests before creating PR
+- Use `/pr create` for consistent PR format
+- Report the PR URL
+
+## Integration
+
+**Called by:**
+- **executing-plans** (Step 6) - After all batches complete
+
+**Uses:**
+- **/pr create** - For pushing and PR creation