fix: statusline crash handling, color validation, git staging rules

Fixed three critical bugs and documented findings:

1. hooks/gsd-statusline.js - Added error handling for file system operations
   - Wrapped fs.readdirSync and fs.statSync in try-catch
   - Prevents crashes from permission errors or race conditions

2. bin/install.js - Added hex color validation
   - Validates hex color format (#RGB or #RRGGBB)
   - Prevents invalid colors from being written to config

3. commands/gsd/execute-phase.md - Fixed git staging violation
   - Replaced 'git add -u' with individual file staging
   - Maintains consistency with documented git commit rules

Documentation:
- BUG_REPORT.md - Comprehensive review findings (8 bugs total)
- FIXES_APPLIED.md - Details of fixes applied and testing recommendations

Known issues remaining:
- JSON config parsing uses fragile grep/sed (requires jq or refactor)
- Documented workarounds and recommendations for future fixes

https://claude.ai/code/session_01RAgU8GfJ2dwtBSmJDGzpWA

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

bin/install.js

@@ -500,8 +500,12 @@ function convertClaudeToOpencodeFrontmatter(content) {
       if (hexColor) {
         newLines.push(`color: "${hexColor}"`);
       } else if (colorValue.startsWith('#')) {
-        // Already hex, keep as is
-        newLines.push(line);
+        // Validate hex color format (#RGB or #RRGGBB)
+        if (/^#[0-9a-f]{3}$|^#[0-9a-f]{6}$/i.test(colorValue)) {
+          // Already hex and valid, keep as is
+          newLines.push(line);
+        }
+        // Skip invalid hex colors
       }
       // Skip unknown color names
       continue;