17a0259cd0
activate_profile: when profile.vector_backend == Lance, auto-migrates
from Parquet if no Lance dataset exists, auto-builds IVF_PQ if no
index attached. Reuses existing Lance dataset on subsequent activations.
profile_scoped_search: routes to Lance IVF_PQ or Parquet+HNSW based
on the profile's declared backend. Callers hit the same endpoint —
the profile abstracts which storage tier serves the query.
Verified: lance-recruiter (vector_backend=lance) and parquet-recruiter
(vector_backend=parquet) both searched the same 100K index through
POST /vectors/profile/{id}/search. Lance returned lance_ivf_pq at
25ms; Parquet returned hnsw at <1ms. Same API surface, different
backends, transparent routing.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>