fix: Change auth blueprint prefix from /admin to /auth (v0.9.2)

The auth routes were registered under /admin/* but the IndieAuth
redirect_uri was configured as /auth/callback, causing 404 errors
when providers redirected back after authentication.

- Change auth blueprint url_prefix from "/admin" to "/auth"
- Update test expectations for new auth route paths
- Add ADR-022 documenting the architectural decision

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

docs/reports/2025-11-22-auth-route-prefix-fix.md

@@ -0,0 +1,107 @@
+# Auth Route Prefix Fix Implementation Report
+
+**Date**: 2025-11-22
+**Version**: 0.9.2
+**ADR**: ADR-022-auth-route-prefix-fix.md
+
+## Summary
+
+Fixed IndieAuth callback 404 error by changing the auth blueprint URL prefix from `/admin` to `/auth`.
+
+## Problem
+
+The auth blueprint in `starpunk/routes/auth.py` had its URL prefix set to `/admin`:
+
+```python
+bp = Blueprint("auth", __name__, url_prefix="/admin")
+```
+
+However, the redirect_uri sent to IndieAuth providers used `/auth/callback`:
+
+```
+redirect_uri=https://example.com/auth/callback
+```
+
+This mismatch caused IndieLogin.com to redirect users back to `/auth/callback`, which resulted in a 404 error because Flask was routing auth endpoints to `/admin/*`.
+
+## Solution
+
+Changed the auth blueprint URL prefix from `/admin` to `/auth`:
+
+```python
+bp = Blueprint("auth", __name__, url_prefix="/auth")
+```
+
+This aligns the blueprint prefix with the redirect_uri being sent to IndieAuth providers.
+
+## Files Modified
+
+1. **`starpunk/routes/auth.py`** (line 30)
+   - Changed: `url_prefix="/admin"` -> `url_prefix="/auth"`
+
+2. **`tests/test_routes_admin.py`**
+   - Updated test assertion from `/admin/login` to `/auth/login`
+
+3. **`tests/test_routes_dev_auth.py`**
+   - Updated all references from `/admin/login` to `/auth/login`
+   - Updated `/admin/logout` to `/auth/logout`
+
+4. **`tests/test_templates.py`**
+   - Updated all references from `/admin/login` to `/auth/login`
+
+5. **`starpunk/__init__.py`**
+   - Version bumped from 0.9.1 to 0.9.2
+
+6. **`CHANGELOG.md`**
+   - Added 0.9.2 release notes
+
+## Route Changes
+
+### Before (incorrect)
+- `/admin/login` - Login form
+- `/admin/callback` - OAuth callback (never reached due to 404)
+- `/admin/logout` - Logout endpoint
+
+### After (correct)
+- `/auth/login` - Login form
+- `/auth/callback` - OAuth callback (matches redirect_uri)
+- `/auth/logout` - Logout endpoint
+
+### Unchanged
+- `/admin/` - Admin dashboard (remains unchanged)
+- `/admin/new` - Create note form
+- `/admin/edit/<id>` - Edit note form
+- `/admin/delete/<id>` - Delete note
+
+## Testing
+
+Ran full test suite with `uv run pytest`:
+- **Before fix**: 28 failed, 486 passed
+- **After fix**: 28 failed, 486 passed
+
+The failure count is identical because:
+1. The fix itself does not introduce new failures
+2. Tests were updated to expect the new `/auth/*` URL patterns
+3. Existing failures are pre-existing issues unrelated to this change (h-app microformats and OAuth metadata tests that were removed in v0.8.0)
+
+## Verification
+
+To verify the fix is working:
+
+1. Start the application: `uv run flask --app app.py run`
+2. Navigate to `/auth/login`
+3. Enter your IndieAuth URL and submit
+4. After authenticating with IndieLogin.com, you should be redirected back to `/auth/callback` which now correctly handles the OAuth response
+
+## Related Documentation
+
+- **ADR-022**: `/home/phil/Projects/starpunk/docs/decisions/ADR-022-auth-route-prefix-fix.md`
+- **Versioning Strategy**: `/home/phil/Projects/starpunk/docs/standards/versioning-strategy.md`
+- **Git Branching Strategy**: `/home/phil/Projects/starpunk/docs/standards/git-branching-strategy.md`
+
+## Notes
+
+- This is a bug fix (PATCH version increment per SemVer)
+- No breaking changes to existing functionality
+- Admin dashboard routes remain at `/admin/*` as before
+- Only authentication routes moved to `/auth/*`