Implement Dashboard consolidation + Performance logging

Features:
- Add unified "Dashboard Complet" sheet (Excel) with all 9 sections
- Add unified "Dashboard Complet" page (PDF) with key metrics
- Fix VALOARE_ANTERIOARA NULL bug (use sumar_executiv_yoy directly)
- Add PerformanceLogger class for timing analysis
- Remove redundant consolidated sheets (keep only Dashboard Complet)

Bug fixes:
- Fix Excel formula error (=== interpreted as formula, changed to >>>)
- Fix args.output → args.output_dir in perf.summary()

Performance analysis:
- Add PERFORMANCE_ANALYSIS.md with detailed breakdown
- SQL queries take 94% of runtime (31 min), Excel/PDF only 1%
- Identified slow queries for optimization

Documentation:
- Update CLAUDE.md with new structure
- Add context handover for query optimization task

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.claude/commands/session-help.md

@@ -0,0 +1,37 @@
+Show help for the session management system:
+
+## Session Management Commands
+
+The session system helps document development work for future reference.
+
+### Available Commands:
+
+- `/project:session-start [name]` - Start a new session with optional name
+- `/project:session-update [notes]` - Add notes to current session  
+- `/project:session-end` - End session with comprehensive summary
+- `/project:session-list` - List all session files
+- `/project:session-current` - Show current session status
+- `/project:session-help` - Show this help
+
+### How It Works:
+
+1. Sessions are markdown files in `.claude/sessions/`
+2. Files use `YYYY-MM-DD-HHMM-name.md` format
+3. Only one session can be active at a time
+4. Sessions track progress, issues, solutions, and learnings
+
+### Best Practices:
+
+- Start a session when beginning significant work
+- Update regularly with important changes or findings
+- End with thorough summary for future reference
+- Review past sessions before starting similar work
+
+### Example Workflow:
+
+```
+/project:session-start refactor-auth
+/project:session-update Added Google OAuth restriction
+/project:session-update Fixed Next.js 15 params Promise issue  
+/project:session-end
+```