docs(mcp): add README, examples, and changelog

- README.md: install/quick start; configs for Claude Desktop, Claude
  Code, and Cursor; programmatic usage; tables covering all 21 tools,
  4 resources, and 3 prompts; limitations; development commands.
- CHANGELOG.md: 0.1.0 entry in Keep a Changelog format.
- examples/generate-apartment.md: prose transcript using from_brief
  to build an 80 m² 2-bed apartment, showing apply_patch, set_zone,
  cut_opening, validate_scene.
- examples/renovate-from-photos.md: prose transcript using the vision
  tools + renovation_from_photos prompt.
- examples/embed-in-agent.ts: compilable TypeScript showing
  programmatic usage via InMemoryTransport.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/mcp/CHANGELOG.md

@@ -0,0 +1,29 @@
+# Changelog
+
+All notable changes to `@pascal-app/mcp` will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [0.1.0] - 2026-04-18
+
+### Added
+
+- Initial release.
+- `SceneBridge` headless adapter for `@pascal-app/core` with RAF polyfill so
+  the Zustand store and Zundo temporal middleware run cleanly in Node.
+- 19 MCP tools covering scene querying (`get_scene`, `get_node`,
+  `describe_node`, `find_nodes`, `measure`), mutation (`apply_patch`,
+  `create_level`, `create_wall`, `place_item`, `cut_opening`, `set_zone`,
+  `duplicate_level`, `delete_node`), undo/redo (`undo`, `redo`), export
+  (`export_json`, `export_glb`), validation (`validate_scene`,
+  `check_collisions`), plus 2 vision tools (`analyze_floorplan_image`,
+  `analyze_room_photo`) backed by MCP sampling.
+- 4 MCP resources: `pascal://scene/current`,
+  `pascal://scene/current/summary`, `pascal://catalog/items`, and
+  `pascal://constraints/{levelId}`.
+- 3 MCP prompts: `from_brief`, `iterate_on_feedback`, and
+  `renovation_from_photos`.
+- stdio and Streamable HTTP transports.
+- `pascal-mcp` CLI binary with `--stdio`, `--http --port`, and `--scene`
+  flags.