Add scripts/memory_budget.py — a CI-friendly tool for checking and
enforcing character budgets on MEMORY.md and USER.md memory files.
Features:
- Checks MEMORY.md vs memory_char_limit (default 2200)
- Checks USER.md vs user_char_limit (default 1375)
- Estimates total injection cost (chars / ~4 chars per token)
- Alerts when approaching limits (>80% usage)
- --report flag for detailed breakdown with progress bars
- --verbose flag for per-entry details
- --enforce flag trims oldest entries to fit budget
- --json flag for machine-readable output (CI integration)
- Exit codes: 0=within budget, 1=over budget, 2=trimmed
- Suggestions for largest entries when over budget
Relates to #256
