Add Cursor CLI as target provider (#179)

* feat(cursor): add Cursor CLI as target provider

Add converter, writer, types, and tests for converting Claude Code
plugins to Cursor-compatible format (.mdc rules, commands, skills,
mcp.json). Agents become Agent Requested rules (alwaysApply: false),
commands are plain markdown, skills copy directly, MCP is 1:1 JSON.

* docs: add Cursor spec and update README with cursor target

* chore: bump CLI version to 0.5.0 for cursor target

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

* docs: note Cursor IDE + CLI compatibility in README

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

src/types/cursor.ts

@@ -0,0 +1,29 @@
+export type CursorRule = {
+  name: string
+  content: string
+}
+
+export type CursorCommand = {
+  name: string
+  content: string
+}
+
+export type CursorSkillDir = {
+  name: string
+  sourceDir: string
+}
+
+export type CursorMcpServer = {
+  command?: string
+  args?: string[]
+  env?: Record<string, string>
+  url?: string
+  headers?: Record<string, string>
+}
+
+export type CursorBundle = {
+  rules: CursorRule[]
+  commands: CursorCommand[]
+  skillDirs: CursorSkillDir[]
+  mcpServers?: Record<string, CursorMcpServer>
+}