Rename the welcome prompt editor from /admin/welcome to /admin/agent-prompt
and update all UI labels to "Agent Setup Prompt". API endpoint URLs are
unchanged (PUT/GET/DELETE /api/admin/welcome-template, GET /api/welcome).
- Nav menu: "Welcome prompt" → "Agent Setup Prompt", href updated
- Page title and h2 updated in admin_welcome.html
- Error message hint in app/api/welcome.py updated to /admin/agent-prompt
- Dashboard: replace inline <details> preview of _claude_setup_instructions
with a simple link to /setup (Task C)
- docs/welcome-template.md renamed to docs/agent-setup-prompt.md; internal
references to /admin/welcome updated
- OpenAPI snapshot path updated
- Tests updated to reflect new route and removed inline preview