New JobPipeline: ordered canonical stages (Applied, Waiting, Interview,
Offer, Rejected, Ghosted) with category grouping and a Normalize() that
canonicalizes casing and known synonyms (Interviewing->Interview,
declined->Rejected, ...) while preserving unknown custom statuses.
- normalize status on every write path (Create/Update/PATCH status) so
the stored value stays canonical without destroying custom values
- GET /api/jobapplications/pipeline exposes the ordered stages so the UI
renders from one source instead of duplicated hardcoded lists
- 14 unit tests; full backend suite green (120)
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
cesnimda