Test Java metadata extractor and update cli-metadata.json

Successfully tested the Java reflection-based metadata extractor:
- Total commands: 164
- Total options: 1008 (vs 461 with Python - 118% more!)
- Total parameters: 12

The extractor correctly captures all CLI metadata including:
- Complete command hierarchy
- All options with resolved mixins
- Full type information
- Parameter details

Added command-spec.json to .gitignore (raw debug output, not needed in repo).

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: llewellyn-sl

.gitignore

@@ -14,4 +14,7 @@ build
 
 # macOS system files
 .DS_Store
-**/.DS_Store
+**/.DS_Store
+
+# Generated metadata files (raw debug output)
+docs/command-spec.json