feat: ε-greedy v1 as active policy; dwell-time reward inference; offline sim framework

- Promote egreedy-v1 to active serving policy (ADR-0007): /score/egreedy + /reward/egreedy
  replaces linucb-v1 endpoints after offline sim shows +10.7% mean reward (−0.548 vs −0.606)
- Replace explicit helpful/not_helpful feedback with dwell-time inferred reward (inferReward):
  dismiss=−1.0, snooze=+0.1, done<15s=−0.3, done 15s–2min=+1.0, done 2–10min=+0.6, done>10min=+0.3
- Add ml/serving ε-greedy endpoints: /score/egreedy, /reward/egreedy, /stats/egreedy/{user_id}
  with d=7 feature vector (base 5 + sin/cos day-of-week encoding)
- Add offline simulation framework (ml/experiments/sim): rule/LLM/claude-code judges,
  two-phase score+reward, synthetic personas, task generator; results stored in sim_runs/sim_events
- Add /admin/simulations page: start runs, live-poll status, reward curve SVG, action/persona tables
- Fix egreedy day_of_week training skew: reward endpoint now uses actual dow instead of hardcoded 0
- Fix runner.py proxy bypass: httpx.Client(trust_env=False) for localhost ML calls
- Add dwellMs to TipFeedbackEvent contract and bus.test.ts fixture
- Schema: sim_runs, sim_events tables; tip_feedback gains dwell_ms, reward_milli columns
- ADR-0006: admin console framework; ADR-0007: egreedy-v1 policy selection rationale

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

services/api/src/test/db.ts

@@ -0,0 +1,84 @@
+/**
+ * Creates an isolated in-memory SQLite DB with the full schema applied.
+ * Use this in tests instead of the shared `db` singleton.
+ */
+import Database from 'better-sqlite3';
+import { drizzle } from 'drizzle-orm/better-sqlite3';
+import * as schema from '../db/schema.js';
+
+export function makeTestDb() {
+  const sqlite = new Database(':memory:');
+  sqlite.pragma('foreign_keys = ON');
+
+  sqlite.exec(`
+    CREATE TABLE IF NOT EXISTS users (
+      id TEXT PRIMARY KEY,
+      email TEXT NOT NULL UNIQUE,
+      name TEXT,
+      image TEXT,
+      google_id TEXT UNIQUE,
+      role TEXT NOT NULL DEFAULT 'user',
+      consent_given INTEGER NOT NULL DEFAULT 0,
+      consent_at TEXT,
+      created_at TEXT NOT NULL,
+      deleted_at TEXT
+    );
+
+    CREATE TABLE IF NOT EXISTS integration_tokens (
+      id TEXT PRIMARY KEY,
+      user_id TEXT NOT NULL REFERENCES users(id),
+      provider TEXT NOT NULL,
+      access_token TEXT NOT NULL,
+      refresh_token TEXT,
+      expires_at TEXT,
+      connected_at TEXT NOT NULL,
+      UNIQUE(user_id, provider)
+    );
+
+    CREATE TABLE IF NOT EXISTS tip_feedback (
+      id TEXT PRIMARY KEY,
+      user_id TEXT NOT NULL REFERENCES users(id),
+      tip_id TEXT NOT NULL,
+      action TEXT NOT NULL,
+      source_id TEXT,
+      created_at TEXT NOT NULL
+    );
+
+    CREATE TABLE IF NOT EXISTS tip_views (
+      id TEXT PRIMARY KEY,
+      user_id TEXT NOT NULL REFERENCES users(id),
+      tip_id TEXT NOT NULL,
+      served_at TEXT NOT NULL
+    );
+
+    CREATE TABLE IF NOT EXISTS push_subscriptions (
+      id TEXT PRIMARY KEY,
+      user_id TEXT NOT NULL REFERENCES users(id),
+      endpoint TEXT NOT NULL UNIQUE,
+      p256dh TEXT NOT NULL,
+      auth TEXT NOT NULL,
+      created_at TEXT NOT NULL
+    );
+
+    CREATE TABLE IF NOT EXISTS sessions (
+      id TEXT PRIMARY KEY,
+      user_id TEXT NOT NULL REFERENCES users(id),
+      expires_at TEXT NOT NULL,
+      created_at TEXT NOT NULL
+    );
+
+    CREATE TABLE IF NOT EXISTS admin_actions (
+      id TEXT PRIMARY KEY,
+      admin_id TEXT NOT NULL REFERENCES users(id),
+      action TEXT NOT NULL,
+      target_type TEXT,
+      target_id TEXT,
+      detail TEXT,
+      created_at TEXT NOT NULL
+    );
+  `);
+
+  return drizzle(sqlite, { schema });
+}
+
+export type TestDb = ReturnType<typeof makeTestDb>;