feat: MCP server + in-repo skills (agent-friendly platform) (#2269)

* feat(api): support global API key from config.yaml (api.global_api_key)

Accept a config-defined global API key anywhere a web-UI key is accepted
(X-API-Key / Bearer), with no login session and no DB record. Useful for
automated deployments and AI agents (HTTP API + MCP). Defaults to empty
(disabled); does not require the lbk_ prefix.

- templates/config.yaml: add api.global_api_key with security notes
- service/apikey.py: verify_api_key checks global key first (constant-time)
- docs/API_KEY_AUTH.md: document the global key + security guidance
- tests: cover global-key match, prefix-free, fallback-to-db, disabled

* feat(mcp): expose LangBot management as an MCP server at /mcp

Add an MCP (Model Context Protocol) server so external AI agents can manage a
LangBot instance. Reuses the same API-key auth as the HTTP API (including the
config.yaml global API key).

- pkg/api/mcp/server.py: FastMCP server wrapping the service layer; 21 curated
  tools across system/bots/pipelines/models/knowledge/mcp-servers/skills
- pkg/api/mcp/mount.py: ASGI dispatcher fronting Quart; authenticates /mcp
  requests with an API key, runs the streamable-HTTP session manager lifespan
- controller/main.py: serve the wrapped ASGI app via hypercorn (was run_task)
- web: new 'MCP' tab in the API integration dialog showing endpoint, auth, and
  client config; i18n for 8 locales
- tests/manual/mcp_smoke.py: e2e check (401 unauth, list tools, call tools)

Tool surface is intentionally curated (not all ~25 route groups) to keep the
agent surface small, safe, and maintainable. Extend deliberately.

* feat(skills): add in-repo skills/ as the single source of truth

Migrate the agent skills + QA/e2e test harness from the (now archived)
langbot-app/langbot-skills repo into LangBot/skills/, and add four new skills.

Migrated:
- langbot-plugin-dev, langbot-testing (e2e), langbot-env-setup,
  langbot-skills-maintenance, langbot-eba-adapter-dev
- the bin/lbs CLI (src/, test/, scripts/, schemas/, qa-agent-docs/)

New:
- langbot-dev      core backend + web development
- langbot-deploy   Docker/K8s deployment + config.yaml + global API key
- langbot-mcp-ops  operating the LangBot MCP server (/mcp)
- langbot-space-ops operating the Space marketplace MCP server

- src/cli.ts repoRoot(): recognize the skills assets root (skills.index.json +
  bin/lbs) so the CLI works when nested inside the LangBot repo
- README.md: unified skill catalog; skills.index.json regenerated

Parity with source verified: bin/lbs validate + node test suite match the
source repo (only the uncommitted .lbpkg build-artifact fixture differs).

* docs(agents): document agent-facing surfaces + API/MCP/skills sync rule

* docs(readme): add 'Built for AI Agents' section across all locales

Highlight MCP server, in-repo skills (single source of truth), AGENTS.md
sync rule, and llms.txt. Cross-link LangBot Space MCP marketplace.

* style(mcp): fix ruff format + prettier lint in MCP server and API panel

* style(web): prettier format MCP i18n locale entries

* docs(skills): note MCP instance control in dev/testing skills

All development-guidance skills now point to the LangBot instance MCP
server (/mcp) and the Space marketplace MCP server, reusing API keys.

README_ES.md

@@ -155,6 +155,17 @@ docker compose up -d
 
 *Nota: Entorno de demostración público. No ingrese información confidencial.*
 
+## Diseñado para Agentes de IA 🤖
+
+LangBot es **agent-friendly por diseño** —— tus agentes de codificación (Claude Code, Codex, Copilot, Cursor, …) pueden operar, extender y desplegar LangBot con soporte de primera clase:
+
+- **Servidor MCP** —— LangBot expone un endpoint integrado de [Model Context Protocol](https://modelcontextprotocol.io/) en `/mcp`, replicando la API HTTP para que un agente gestione bots, pipelines, plugins y modelos de forma programática. Autentícate con la misma API key (configura una clave global en `config.yaml` o usa una clave por usuario) —— sin flujo de login. Configúralo en la pestaña **API & MCP** del panel web.
+- **Skills en el repositorio** —— El directorio [`skills/`](skills/) es la **única fuente de verdad** para trabajar con LangBot: desarrollo de plugins, desarrollo del core, pruebas end-to-end, despliegue y operación de los servidores MCP de LangBot / LangBot Space. Apunta tu agente a este directorio y sabrá cómo construir.
+- **AGENTS.md** —— Cada repo incluye un [`AGENTS.md`](AGENTS.md) (enlazado simbólicamente a `CLAUDE.md`) que describe la arquitectura, las convenciones y la regla de que los cambios en la API deben mantener sincronizados el servidor MCP y los skills.
+- **`llms.txt`** —— El contexto del proyecto legible por máquina para LLMs está publicado en el sitio web.
+
+> **Nube / Marketplace:** [LangBot Space](https://space.langbot.app) también expone un servidor MCP para que los agentes busquen e inspeccionen el marketplace de plugins / MCP / skills, autenticados con un Personal Access Token.
+
 ---
 
 ## Comunidad