feat: Phase 0 walking skeleton — monorepo, API, web, ML stub

Sets up the full Phase 0 foundation:

- pnpm workspaces + turbo build graph; native module build approval
- packages/shared-types: HTTP contracts (Tip, Auth, Integrations, User)
- services/api: Express modular monolith with better-sqlite3/drizzle
  - auth: Google OAuth2 + PKCE via openid-client v6, cookie sessions
  - integrations: Todoist OAuth2 connect/disconnect, token vault
  - recommender: RandomPolicy over Todoist tasks, feedback sink
  - user: profile, consent capture, full account deletion (GDPR)
- apps/web: Next.js 15, three pages (sign-in → connect → tip)
  - tip page: black canvas, hold-to-act gesture, action sheet
  - PWA manifest + theme
- ml/serving: FastAPI stub implementing the POST /score contract
- infra: docker-compose (core/full profiles), Dockerfiles, CI skeleton
- .env.example with all required vars documented

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

services/api/src/db/schema.ts

@@ -0,0 +1,39 @@
+import { sqliteTable, text, integer } from 'drizzle-orm/sqlite-core';
+
+export const users = sqliteTable('users', {
+  id: text('id').primaryKey(),
+  email: text('email').notNull().unique(),
+  name: text('name'),
+  image: text('image'),
+  googleId: text('google_id').unique(),
+  consentGiven: integer('consent_given', { mode: 'boolean' }).notNull().default(false),
+  consentAt: text('consent_at'),
+  createdAt: text('created_at').notNull(),
+  deletedAt: text('deleted_at'),
+});
+
+export const integrationTokens = sqliteTable('integration_tokens', {
+  id: text('id').primaryKey(),
+  userId: text('user_id').notNull().references(() => users.id),
+  provider: text('provider').notNull(), // 'todoist'
+  accessToken: text('access_token').notNull(),
+  refreshToken: text('refresh_token'),
+  expiresAt: text('expires_at'),
+  connectedAt: text('connected_at').notNull(),
+});
+
+export const tipFeedback = sqliteTable('tip_feedback', {
+  id: text('id').primaryKey(),
+  userId: text('user_id').notNull().references(() => users.id),
+  tipId: text('tip_id').notNull(),
+  action: text('action').notNull(), // 'done' | 'dismiss' | 'snooze'
+  sourceId: text('source_id'),
+  createdAt: text('created_at').notNull(),
+});
+
+export const sessions = sqliteTable('sessions', {
+  id: text('id').primaryKey(),
+  userId: text('user_id').notNull().references(() => users.id),
+  expiresAt: text('expires_at').notNull(),
+  createdAt: text('created_at').notNull(),
+});