🟡 MEDIUM: Address 30+ TODO/FIXME comments

## Problem

The codebase contains **30+ TODO/FIXME comments** indicating incomplete implementation or known issues.

## Notable Examples

| File | Line | Comment |
|------|------|---------|
| `AuthenticationManager.swift` | 187 | `// FIXME: major issue - user is lost from the backend` |
| `ArkavoMessageRouter.swift` | 78 | `// FIXME: hack, not sure why I am getting 064c31` |
| `ChatView.swift` | 348 | `// TODO: Notify user of failure` |

## Impact

- Technical debt accumulating
- Known bugs not being tracked
- Incomplete features shipped
- Difficult to assess project health

## Solution

1. Audit all TODO/FIXME comments
2. Create GitHub issues for each significant one
3. Either fix immediately or add to backlog
4. Remove or update comments after addressing

## Acceptance Criteria

- [ ] All TODO/FIXME comments audited
- [ ] Critical ones converted to issues
- [ ] Non-critical ones documented in backlog
- [ ] No orphaned TODO comments

Search the codebase for TODO and FIXME comments, then review the examples in AuthenticationManager.swift, ArkavoMessageRouter.swift, and ChatView.swift. Audit each comment, create issues for significant items, document non-critical items in the backlog, and remove or update orphaned comments.

Written by the indexing model from the issue text.