chore(roo): document git-based wiki workflow in rules, skill, and README

- mcp-builder rules: add wiki/ to structure diagram, add Wiki Update
  Workflow section (MANDATORY), update After Building a Server checklist
- gitea-push skill: add wiki deploy as a valid use case
- README.md: add wiki section with deploy_wiki.sh pointer, add
  mcp-image-gen to MCP servers table

README.md

@@ -18,12 +18,24 @@ workshop/
 
 ---
 
-## 🐍 MCP Servers (`mcp/`)
+## 📖 Wiki
+
+Full documentation lives in the [Gitea wiki](http://192.168.188.119:30008/pplate/pi_mcps/wiki).
+
+**Wiki source:** [`docs/wiki/pages/`](docs/wiki/pages/) — edit here, deploy with:
+```bash
+./docs/wiki/deploy_wiki.sh
+```
+
+---
+
+## � MCP Servers (`mcp/`)
 
 | Server | Description | Stack |
 |---|---|---|
 | [`mcp/bigmind/`](mcp/bigmind/) | Persistent AI memory — sessions, facts, hypotheses, profile UI | Python, FastMCP, SQLite, Flask |
-| [`mcp/webscraper/`](mcp/webscraper/) | Web scraping — fetch, links, tables, sections, sitemaps | Python, FastMCP, httpx, BeautifulSoup |
+| [`mcp/webscraper/`](mcp/webscraper/) | Web scraping, search — fetch, links, tables, Brave Search | Python, FastMCP, httpx, BeautifulSoup |
+| [`mcp/mcp-image-gen/`](mcp/mcp-image-gen/) | AI image generation — text-to-image via ComfyUI + FLUX.1-schnell | Python, FastMCP, httpx, ComfyUI |
 
 **Run a server:**
 ```bash