feat: rework EOL, repairs, and hosts for real workflow

Four domain-model changes driven by exercising the deployed 2.0 build:

- EOL moves from manufacturer to MPN via new PartModel catalog table,
  so alerts fire on the thing that actually ages.
- Repairs re-home to Host (required hostId + problem text) with an
  optional RepairJobPart join for affected parts; drop Part.replacementPartId.
- New /repairs/:id detail page with editable problem, part list, and
  a RepairComment thread (REPAIR_COMMENTED events fan out to each
  problem part's timeline).
- Host.assetId (required, unique) surfaces prominently on the repair
  page so techs can confirm they're touching the right box.

Single destructive migration reshapes existing dev data. All 7 packages
typecheck clean; 30 API tests pass (9 new covering host membership,
upsertByMpn idempotency + race, assetId 409, comment userId stamping).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

apps/api/src/app.ts

@@ -14,6 +14,7 @@ import { errorHandler } from './middleware/error.js';
 import authRoutes from './routes/auth.js';
 import userRoutes from './routes/users.js';
 import manufacturerRoutes from './routes/manufacturers.js';
+import partModelRoutes from './routes/part-models.js';
 import siteRoutes from './routes/sites.js';
 import roomRoutes from './routes/rooms.js';
 import binRoutes from './routes/bins.js';
@@ -79,6 +80,7 @@ app.use('/api/auth', authLimiter, authRoutes);
 app.use('/api', requireCsrf);
 app.use('/api/users', userRoutes);
 app.use('/api/manufacturers', manufacturerRoutes);
+app.use('/api/part-models', partModelRoutes);
 app.use('/api/sites', siteRoutes);
 app.use('/api/rooms', roomRoutes);
 app.use('/api/bins', binRoutes);