feat: add name field to npubs

[sh1ftred]

Summary

Adds an optional name field to registered npubs, allowing admins to assign human-readable labels to npub entries. This works the same way as the existing role field — set it at creation time, update it later.

Changes

• DB schema: New nullable name column on routstr_auth_npubs table, auto-migrated from older DBs via ALTER TABLE ADD COLUMN
• NpubEntry interface: Added name: string | null
• AuthStore.addNpub(): Accepts optional name parameter
• AuthStore.updateNpubName(): New method (mirrors updateNpubRole())
• POST /npubs: Accepts optional "name" field in the body
• PATCH /npubs: Now accepts "role" and/or "name" (at least one required, admin-only)
• GET /npubs: Includes name in the response
• Validation: name must be a string or null; passing anything else returns a 400 error

API Usage for External Clients

Set a name when adding an npub

curl -X POST http://localhost:8008/npubs \
  -H "Authorization: Nostr <base64-event>" \
  -H "Content-Type: application/json" \
  -d '{"npub": "npub1...", "role": "user", "name": "Alice"}'

Update an npub's name (admin only)

Just like updating a role, use PATCH /npubs with NIP-98 admin auth:

# Update name only
curl -X PATCH http://localhost:8008/npubs \
  -H "Authorization: Nostr <base64-event>" \
  -H "Content-Type: application/json" \
  -d '{"npub": "npub1...", "name": "Bob"}'

# Update both role and name in a single request
curl -X PATCH http://localhost:8008/npubs \
  -H "Authorization: Nostr <base64-event>" \
  -H "Content-Type: application/json" \
  -d '{"npub": "npub1...", "role": "admin", "name": "Bob"}'

# Clear a name by setting it to null
curl -X PATCH http://localhost:8008/npubs \
  -H "Authorization: Nostr <base64-event>" \
  -H "Content-Type: application/json" \
  -d '{"npub": "npub1...", "name": null}'

List npubs with names

curl http://localhost:8008/npubs
# => { "npubs": [{ "npub": "npub1...", "name": "Alice", "role": "admin" }, ...] }

Backward Compatibility

• Existing DBs are auto-migrated; the name column is added on first run
• The name field is optional in all request bodies (defaults to null)
• The PATCH /npubs endpoint previously required role; now it requires at least one of role or name