Second Brain: Agent API keys generated

## Generated Keys For
- bob: sb_bob_ea4ec...
- kai: sb_kai_d6c1c...
- atlas: sb_atlas_99b5...
- sage: sb_sage_b9226...
- maya: sb_maya_5f6eb...

## Storage
- Keys stored in `/home/henryk/clawd/.brain-keys`
- File is gitignored and chmod 600
- Each agent sources their key from this file

## Key Format
`sb_<agent>_<32-char-random>`

## Permissions
- bob: read, write, delete
- others: read, write

## How to Use
```bash
source ~/.brain-keys
curl -H "Authorization: Bearer $BOB_BRAIN_KEY" https://brain.widerwings.com/api/memories
```