docs: update Last Updated date and Claude Code version across all files

Update all documentation footers from generic "April 2026 / 2.1+" to
the specific sync date (April 9, 2026) and documented version (2.3.0).
Also add version/date footers to zh/CATALOG.md and
zh/01-slash-commands/README.md which were missing them.

Generated with [Claude Code](https://claude.ai/code)
via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

04-subagents/README.md

@@ -1137,6 +1137,6 @@ graph TD
 - [Hooks Guide](../06-hooks/) - For event-driven automation
 
 ---
-**Last Updated**: April 2026
-**Claude Code Version**: 2.1+
+**Last Updated**: April 9, 2026
+**Claude Code Version**: 2.3.0
 **Compatible Models**: Claude Sonnet 4.6, Claude Opus 4.6, Claude Haiku 4.5

04-subagents/clean-code-reviewer.md

@@ -66,4 +66,4 @@ Fix: [how to fix]
 **Core Philosophy**: Code is read 10x more than written. Optimize for readability, not cleverness.
 
 ---
-**Last Updated**: April 2026
+**Last Updated**: April 9, 2026

04-subagents/code-reviewer.md

@@ -61,4 +61,4 @@ Include specific examples of how to fix issues.
 - **Impact**: Response time increases linearly with data size
 
 ---
-**Last Updated**: April 2026
+**Last Updated**: April 9, 2026

04-subagents/data-scientist.md

@@ -97,4 +97,4 @@ ORDER BY 1 DESC;
 - [ ] Recommendations provided
 
 ---
-**Last Updated**: April 2026
+**Last Updated**: April 9, 2026

04-subagents/debugger.md

@@ -80,4 +80,4 @@ npm test -- --grep "test name"
 - [ ] No regressions introduced
 
 ---
-**Last Updated**: April 2026
+**Last Updated**: April 9, 2026

04-subagents/documentation-writer.md

@@ -98,4 +98,4 @@ curl -X GET https://api.example.com/api/users/abc123 \
 ```
 
 ---
-**Last Updated**: April 2026
+**Last Updated**: April 9, 2026

04-subagents/implementation-agent.md

@@ -78,4 +78,4 @@ Before marking complete:
 - [ ] Error handling implemented
 
 ---
-**Last Updated**: April 2026
+**Last Updated**: April 9, 2026

04-subagents/performance-optimizer.md

@@ -126,4 +126,4 @@ For each optimization delivered:
 - [ ] Monitoring / alerting recommended
 
 ---
-**Last Updated**: April 2026
+**Last Updated**: April 9, 2026

04-subagents/secure-reviewer.md

@@ -75,4 +75,4 @@ For each vulnerability:
 - **Remediation**: How to fix it
 
 ---
-**Last Updated**: April 2026
+**Last Updated**: April 9, 2026

04-subagents/test-engineer.md

@@ -74,4 +74,4 @@ describe('Feature: User Authentication', () => {
 ```
 
 ---
-**Last Updated**: April 2026
+**Last Updated**: April 9, 2026