Windsurf + Aider targets, MCP server, and demo placement (#33)

Broadens both reach (more tools) and content types (an MCP server), continuing
the multi-platform story.

Windsurf + Aider:
- build-exports.mjs gains two platforms: exports/windsurf/*.md (workspace rules,
  trigger: model_decision) and exports/aider/*.md (conventions for `aider --read`).
  Now 5 platforms (ChatGPT, Gemini, Cursor, Windsurf, Aider).
- install.sh + bin/cli.mjs install both (windsurf -> .windsurf/rules, aider ->
  .aider/skills with a --read hint); generated README index is excluded from copies.
- One-line windsurf-install.sh / aider-install.sh wrappers for parity.

MCP server (new content type):
- mcp/server.mjs — zero-dependency stdio MCP server exposing list_skills,
  search_skills, get_skill. Published as a second bin (pm-claude-skills-mcp).
  Logs to stderr; reads bundled skills/ at startup. mcp/README.md documents
  client config.

Also: README hero "See it in action" demo placement (ready to swap in a GIF;
recording guide in web/docs-assets/README.md), Works-With table + exports +
install docs updated, CHANGELOG Unreleased. package.json files/bin updated.


Claude-Session: https://claude.ai/code/session_016JWn5jRD5tcEFKrubjQ6Px

Co-authored-by: Claude <noreply@anthropic.com>

CHANGELOG.md

@@ -10,6 +10,16 @@ each new wave of skills bumps the **major** version, extensions and fixes bump
 ## [Unreleased]
 
 ### Added
+- **MCP server** — `mcp/server.mjs`, a zero-dependency Model Context Protocol server
+  (stdio) exposing `list_skills`, `search_skills`, and `get_skill` so MCP clients (Claude
+  Desktop, Cline, …) pull skills on demand. Published as a second bin,
+  `npx pm-claude-skills-mcp`.
+- **Windsurf & Aider targets** — two more export platforms (`exports/windsurf/*.md`
+  workspace rules, `exports/aider/*.md` conventions) and install support in `install.sh`,
+  the `npx` CLI, and one-line `windsurf-install.sh` / `aider-install.sh`. The library now
+  exports to **5 platforms** (ChatGPT, Gemini, Cursor, Windsurf, Aider).
+- **Hero demo placement** — README "See it in action" block linking to the live Playground,
+  ready to swap a `playground-demo.gif` in (recording guide in `web/docs-assets/README.md`).
 - **Automated npm publishing** — `.github/workflows/npm-publish.yml` publishes the package
   to npm (with provenance) when a GitHub Release is published. Requires a one-time
   `NPM_TOKEN` repo secret; no local npm needed.