Add Ingest as a dedicated mode tab in the Studio pipeline
(Configure → Verify → Prepare → Ingest). Create IngestPanel
component in features/ingestion/ui/ with summary, stepper,
and action button. Remove orphan Ingest button and inline
stepper from StudioPage. Remove auto-ingest on analysis complete.
Closes#160
Move chunk search from DocumentsPage into a new Search bounded context
(features/search/) with its own store, API layer, page and route.
Clean search state out of the ingestion module.
Closes#159
Backend: GET /api/ingestion/search?q=…&doc_id=… endpoint with
SearchResponse schema. Frontend: search bar in Documents page, results
with filename, page, chunk index, relevance score. 3 new API tests.
Visual stepper in Studio topbar: Embedding → Indexing → Done.
Each step shows pending/active/done with animated dot. Store tracks
currentStep through the pipeline. Auto-resets after 2s.
