[Reviewed] feat: Add permission middleware for command access control (Item 3)

[messiawrq-spec]

Claims and resolves Item #10 from Issue #40.

Added src/middleware/permissions.js to intercept and validate user permissions prior to command execution. Automatically replies with an ephemeral missing permission message if the user doesn't meet the requirement.

[TrivCodez]

Summary

Creates reusable permission validation middleware for checking user permissions before command execution. Good modular design for permission management.

🔴 Critical

• No critical issues - Permission checking logic is correct

🟡 Warnings

File	Line	Severity	Issue	Fix
src/middleware/permissions.js	7	Low	Empty permissions array [] should probably fail fast or be documented	Add guard: if (!permissions.length) throw new Error('Permissions array cannot be empty')
src/middleware/permissions.js	8	Medium	Uses interaction.member but doesn't handle case where it's null	Add null check: if (!interaction.member) return false;

🟢 Suggestions

1. Add JSDoc with example usage showing permission strings format
2. Consider adding support for OR logic (user needs ANY of permissions, not ALL)
3. Add caching for member permissions to reduce API calls
4. Include permission constants export (e.g., Permissions.SendMessages)
5. Add unit tests for edge cases (null member, missing permissions, bot permissions)

✅ Good

• Clean middleware pattern - easy to integrate
• Clear error messages with missing permission names
• Uses Discord.js PermissionFlagsBitfield correctly
• Properly handles admin bypass
• Good separation from command logic

Approved ✅ Ready to merge with minor suggestions.