feat(profile): user-profile feature registry + builder (phase A)

Centralizes user-level features (completion_rate_30d, dismiss_rate_30d,
mean_dwell_ms_30d, preferred_hour, tip_volume_30d) in a TS registry that
owns both definition and SQL aggregation, since the data lives in the
TS-owned SQLite tables (tip_views/tip_feedback). Lazy TTL refresh keeps
recommend latency bounded; values persist in user_profile_features (KV).

ml/serving accepts profile_features on /score + /generate but does not
yet consume them — extending the bandit feature vector changes D and
resets every user's learned state, so that's a deliberate phase-B step.

Includes ml/features/profile_schema.py as a contract mirror with a sync
test that diffs name sets against registry.ts.

ADR-0011 records the data-locality reasoning (registry in TS, not Python
as the issue originally suggested).

Phase B (deferred): event-driven incremental updates, bandit consumption
with state migration, admin per-user profile page, staleness alerts.

Refs #81.

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

services/api/src/test/db.ts

@@ -105,6 +105,16 @@ export function makeTestDb(): DrizzleDb & { rawSqlite: BetterSqlite3Database } {
       created_at TEXT NOT NULL
     );
 
+    CREATE TABLE IF NOT EXISTS user_profile_features (
+      user_id TEXT NOT NULL REFERENCES users(id),
+      name TEXT NOT NULL,
+      value REAL,
+      value_text TEXT,
+      updated_at TEXT NOT NULL,
+      ttl_sec INTEGER NOT NULL,
+      PRIMARY KEY (user_id, name)
+    );
+
     CREATE TABLE IF NOT EXISTS sim_runs (
       id TEXT PRIMARY KEY,
       policy_a TEXT NOT NULL,