feat: add Cursor IDE support with pre-translated configs

Add complete .cursor/ directory with rules, agents, skills, commands,
and MCP config adapted for Cursor's format. This makes ecc-universal
a truly cross-IDE package supporting Claude Code, Cursor, and OpenCode.

- 27 rule files with YAML frontmatter (description, globs, alwaysApply)
- 13 agent files with full model IDs and readonly flags
- 30 skill directories (identical Agent Skills standard, no translation)
- 31 command files (5 multi-* stubbed for missing codeagent-wrapper)
- MCP config with Cursor env interpolation syntax
- README.md and MIGRATION.md documentation
- install.sh --target cursor flag for project-scoped installation
- package.json updated with .cursor/ in files and cursor keywords

.cursor/commands/code-review.md

@@ -0,0 +1,40 @@
+# Code Review
+
+Comprehensive security and quality review of uncommitted changes:
+
+1. Get changed files: git diff --name-only HEAD
+
+2. For each changed file, check for:
+
+**Security Issues (CRITICAL):**
+- Hardcoded credentials, API keys, tokens
+- SQL injection vulnerabilities
+- XSS vulnerabilities
+- Missing input validation
+- Insecure dependencies
+- Path traversal risks
+
+**Code Quality (HIGH):**
+- Functions > 50 lines
+- Files > 800 lines
+- Nesting depth > 4 levels
+- Missing error handling
+- console.log statements
+- TODO/FIXME comments
+- Missing JSDoc for public APIs
+
+**Best Practices (MEDIUM):**
+- Mutation patterns (use immutable instead)
+- Emoji usage in code/comments
+- Missing tests for new code
+- Accessibility issues (a11y)
+
+3. Generate report with:
+   - Severity: CRITICAL, HIGH, MEDIUM, LOW
+   - File location and line numbers
+   - Issue description
+   - Suggested fix
+
+4. Block commit if CRITICAL or HIGH issues found
+
+Never approve code with security vulnerabilities!