Phase 17: Model profiles + scoped search — the LLM-brain keystone

Implements PRD invariant 9 ("every reader gets its own profile") and
completes the multi-model substrate vision. Local models (or agents)
bind to a named set of datasets; activation pre-loads their vector
indexes into memory; search enforces scope.

Schema (shared::types):
- ModelProfile { id, ollama_name, description, bound_datasets,
                 hnsw_config, embed_model, created_at, created_by }
- ProfileHnswConfig mirrors vectord::trial::HnswConfig to avoid a
  cross-crate dep cycle. Default (ec=80, es=30) matches the Phase 15
  trial winner.
- bound_datasets can reference raw dataset names OR AiView names
  (both register as DataFusion tables with the same name, so mixing
  raw tables and PII-redacted views composes naturally)

Catalog (catalogd::registry):
- put_profile validates id is a slug (alphanumeric + -_ only) and
  every binding resolves to an existing dataset or view
- Persistence at _catalog/profiles/{id}.json, loaded on rebuild
- get_profile / list_profiles / delete_profile

HTTP endpoints:
- POST /catalog/profiles  (create/update)
- GET  /catalog/profiles  (list)
- GET/DELETE /catalog/profiles/{id}
- POST /vectors/profile/{id}/activate  (HNSW hot-load)
- POST /vectors/profile/{id}/search    (scope-enforced)

Activation (vectord::service::activate_profile):
- For each bound dataset, find vector indexes with matching source
- Pre-load embeddings into EmbeddingCache
- Build HNSW with profile's config
- Report warmed indexes + per-binding failures + duration
- Failures on individual bindings don't abort — "substrate keeps
  working" per ADR-017

Scoped search (vectord::service::profile_scoped_search):
- Look up profile, verify index.source ∈ profile.bound_datasets
- Returns 403 with allowed bindings list if out-of-scope
- Uses HNSW if index is warm, brute-force cosine otherwise (graceful
  degradation — no "must activate first" friction)

Bug fix surfaced during testing: vectord::refresh::try_update_index_meta
was a no-op for first-time indexes, so threat_intel_v1 and
kb_team_runs_v1 (both built via refresh after Phase C shipped) didn't
show up in the index registry. Now it auto-infers the source from the
index name convention (`{source}_vN`) and registers new metadata with
reasonable defaults.

End-to-end verified:
- Created security-analyst profile bound to [threat_intel]
- POST /vectors/profile/security-analyst/activate → warmed
  threat_intel_v1 (54 vectors) in 156ms, HNSW built
- Within-scope search: method=hnsw, returned relevant IP indicators
- Out-of-scope: tried to search resumes_100k_v2 (source=candidates)
  → 403 "profile 'security-analyst' is not bound to 'candidates' —
    allowed bindings: [\"threat_intel\"]"
- staffing-recruiter profile created bound to candidates + placements;
  search without activation fell through to brute_force (graceful)

Deferred (Phase 17 followups):
- VRAM-aware activation (unload-then-load via Ollama keep_alive=0)
  — Ollama already handles this; we don't need to reinvent
- Model-identity in audit trail — Phase 13 has role-based audit;
  adding model_id is ~20 LOC when we want it
- Profile bucket pre-load (profile:user bucket mount) — Phase 17.5

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/PHASES.md

@@ -154,6 +154,15 @@
   - `crates/lance-bench` standalone pilot (Lance 4.0) avoids DataFusion/Arrow version conflict with main stack
   - 8-dimension benchmark on resumes_100k_v2 — see docs/ADR-019-vector-storage.md for scorecard
   - Decision: hybrid architecture. Parquet+HNSW stays primary (2.55× faster search at 100K in-RAM). Lance added as per-profile second backend for random access (112× faster), append (0.08s vs full rewrite), hot-swap (14× faster index builds), and scale past 5M RAM ceiling.
+- [x] Phase 17: Model profiles + scoped search — 2026-04-16
+  - `shared::types::ModelProfile` — { id, ollama_name, description, bound_datasets, hnsw_config, embed_model, created_at, created_by }
+  - `shared::types::ProfileHnswConfig` — mirror of vectord's HnswConfig to avoid cross-crate dep cycle (defaults ec=80 es=30 matching Phase 15 winner)
+  - `Registry::{put_profile, get_profile, list_profiles, delete_profile}` persisted at `_catalog/profiles/{id}.json`, validates bindings exist (raw dataset OR AiView)
+  - Endpoints: `POST/GET /catalog/profiles`, `GET/DELETE /catalog/profiles/{id}`
+  - `POST /vectors/profile/{id}/activate` — warms EmbeddingCache + builds HNSW with profile's config for every bound dataset's vector index; reports warmed indexes + failures + duration
+  - `POST /vectors/profile/{id}/search` — rejects 403 if requested index's source isn't in profile.bound_datasets; falls through to HNSW if warm, brute-force otherwise
+  - Fixed refresh to register new index metadata (was silently no-op for first-time indexes)
+  - End-to-end: security-analyst profile bound to threat_intel → activate warms 54 vectors in 156ms → within-scope HNSW search works (0.625 score); out-of-scope search for candidates returns 403 with allowed bindings listed
 - [x] Phase E: Soft deletes (tombstones) — 2026-04-16
   - `shared::types::Tombstone` — { dataset, row_key_column, row_key_value, deleted_at, actor, reason }
   - `catalogd::tombstones::TombstoneStore` per-dataset append-log at `_catalog/tombstones/{dataset}/`, flush_threshold=1 + explicit flush so every tombstone is durable on return (compliance requirement)