feat: add Terms & Conditions checkbox to signup (refs #4)

- Add terms_agreements table for legal audit trail
- Create terms-agreement feature capsule with repository
- Modify signup to create terms agreement atomically
- Add checkbox with PDF link to SignupForm
- Capture IP, User-Agent, terms version, content hash
- Update CLAUDE.md documentation index

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/src/features/CLAUDE.md

@@ -16,6 +16,7 @@ Feature capsule directory. Each feature is 100% self-contained with api/, domain
 | `onboarding/` | User onboarding flow | First-time user setup |
 | `platform/` | Vehicle data and VIN decoding | Make/model lookup, VIN validation |
 | `stations/` | Gas station search and favorites | Google Maps integration, station data |
+| `terms-agreement/` | Terms & Conditions acceptance audit | Signup T&C, legal compliance |
 | `user-export/` | User data export | GDPR compliance, data portability |
 | `user-preferences/` | User preference management | User settings API |
 | `user-profile/` | User profile management | Profile CRUD, avatar handling |

backend/src/features/auth/api/auth.controller.ts

@@ -6,6 +6,8 @@
 import { FastifyRequest, FastifyReply } from 'fastify';
 import { AuthService } from '../domain/auth.service';
 import { UserProfileRepository } from '../../user-profile/data/user-profile.repository';
+import { TermsAgreementRepository } from '../../terms-agreement/data/terms-agreement.repository';
+import { termsConfig } from '../../terms-agreement/domain/terms-config';
 import { pool } from '../../../core/config/database';
 import { logger } from '../../../core/logging/logger';
 import { signupSchema, resendVerificationPublicSchema } from './auth.validation';
@@ -15,7 +17,22 @@ export class AuthController {
 
   constructor() {
     const userProfileRepository = new UserProfileRepository(pool);
-    this.authService = new AuthService(userProfileRepository);
+    const termsAgreementRepository = new TermsAgreementRepository(pool);
+    this.authService = new AuthService(userProfileRepository, termsAgreementRepository);
+  }
+
+  /**
+   * Extract client IP address from request
+   * Checks X-Forwarded-For header for proxy scenarios (Traefik)
+   */
+  private getClientIp(request: FastifyRequest): string {
+    const forwardedFor = request.headers['x-forwarded-for'];
+    if (forwardedFor) {
+      // X-Forwarded-For can be comma-separated list; first IP is the client
+      const ips = Array.isArray(forwardedFor) ? forwardedFor[0] : forwardedFor;
+      return ips.split(',')[0].trim();
+    }
+    return request.ip || 'unknown';
   }
 
   /**
@@ -34,9 +51,18 @@ export class AuthController {
         });
       }
 
-      const { email, password } = validation.data;
+      const { email, password, termsAccepted } = validation.data;
 
-      const result = await this.authService.signup({ email, password });
+      // Extract terms data for audit trail
+      const termsData = {
+        ipAddress: this.getClientIp(request),
+        userAgent: (request.headers['user-agent'] as string) || 'unknown',
+        termsVersion: termsConfig.version,
+        termsUrl: termsConfig.url,
+        termsContentHash: termsConfig.getContentHash(),
+      };
+
+      const result = await this.authService.signup({ email, password, termsAccepted }, termsData);
 
       logger.info('User signup successful', { email, userId: result.userId });
 

backend/src/features/auth/api/auth.validation.ts

@@ -18,6 +18,9 @@ const passwordSchema = z
 export const signupSchema = z.object({
   email: z.string().email('Invalid email format'),
   password: passwordSchema,
+  termsAccepted: z.literal(true, {
+    errorMap: () => ({ message: 'You must agree to the Terms & Conditions to create an account' }),
+  }),
 });
 
 export type SignupInput = z.infer<typeof signupSchema>;

backend/src/features/auth/domain/auth.service.ts

@@ -5,6 +5,8 @@
 
 import { auth0ManagementClient } from '../../../core/auth/auth0-management.client';
 import { UserProfileRepository } from '../../user-profile/data/user-profile.repository';
+import { TermsAgreementRepository } from '../../terms-agreement/data/terms-agreement.repository';
+import { pool } from '../../../core/config/database';
 import { logger } from '../../../core/logging/logger';
 import {
   SignupRequest,
@@ -13,17 +15,21 @@ import {
   ResendVerificationResponse,
   SecurityStatusResponse,
   PasswordResetResponse,
+  TermsData,
 } from './auth.types';
 
 export class AuthService {
-  constructor(private userProfileRepository: UserProfileRepository) {}
+  constructor(
+    private userProfileRepository: UserProfileRepository,
+    private termsAgreementRepository: TermsAgreementRepository
+  ) {}
 
   /**
    * Create a new user account
    * 1. Create user in Auth0 (which automatically sends verification email)
-   * 2. Create local user profile with emailVerified=false
+   * 2. Create local user profile and terms agreement atomically
    */
-  async signup(request: SignupRequest): Promise<SignupResponse> {
+  async signup(request: SignupRequest, termsData: TermsData): Promise<SignupResponse> {
     const { email, password } = request;
 
     try {
@@ -36,14 +42,42 @@ export class AuthService {
 
       logger.info('Auth0 user created', { auth0UserId, email });
 
-      // Create local user profile
-      const userProfile = await this.userProfileRepository.create(
-        auth0UserId,
-        email,
-        undefined // displayName is optional
-      );
+      // Create local user profile and terms agreement in a transaction
+      const client = await pool.connect();
+      try {
+        await client.query('BEGIN');
 
-      logger.info('User profile created', { userId: userProfile.id, email });
+        // Create user profile
+        const profileQuery = `
+          INSERT INTO user_profiles (auth0_sub, email, subscription_tier)
+          VALUES ($1, $2, 'free')
+          RETURNING id
+        `;
+        const profileResult = await client.query(profileQuery, [auth0UserId, email]);
+        const profileId = profileResult.rows[0].id;
+
+        logger.info('User profile created', { userId: profileId, email });
+
+        // Create terms agreement
+        await this.termsAgreementRepository.create({
+          userId: auth0UserId,
+          ipAddress: termsData.ipAddress,
+          userAgent: termsData.userAgent,
+          termsVersion: termsData.termsVersion,
+          termsUrl: termsData.termsUrl,
+          termsContentHash: termsData.termsContentHash,
+        }, client);
+
+        logger.info('Terms agreement created', { userId: auth0UserId });
+
+        await client.query('COMMIT');
+      } catch (error) {
+        await client.query('ROLLBACK');
+        logger.error('Transaction failed, rolling back', { error, email });
+        throw error;
+      } finally {
+        client.release();
+      }
 
       return {
         userId: auth0UserId,

backend/src/features/auth/domain/auth.types.ts

@@ -7,6 +7,16 @@
 export interface SignupRequest {
   email: string;
   password: string;
+  termsAccepted: boolean;
+}
+
+// Terms data captured during signup for audit trail
+export interface TermsData {
+  ipAddress: string;
+  userAgent: string;
+  termsVersion: string;
+  termsUrl: string;
+  termsContentHash: string;
 }
 
 // Response from signup endpoint

backend/src/features/terms-agreement/README.md

@@ -0,0 +1,46 @@
+# Terms Agreement Feature
+
+Stores legal audit trail for Terms & Conditions acceptance at user signup.
+
+## Purpose
+
+Provides comprehensive legal compliance by capturing:
+- **User consent**: Proof that user agreed to T&C before account creation
+- **Audit fields**: IP address, user agent, timestamp, terms version, content hash
+
+## Data Flow
+
+1. User checks T&C checkbox on signup form
+2. Frontend sends `termsAccepted: true` with signup request
+3. Controller extracts IP (from X-Forwarded-For header), User-Agent
+4. Service creates user profile and terms agreement atomically in transaction
+5. Terms agreement record stores audit fields for legal compliance
+
+## Database Schema
+
+| Column | Type | Description |
+|--------|------|-------------|
+| id | UUID | Primary key |
+| user_id | VARCHAR | Auth0 user ID |
+| agreed_at | TIMESTAMPTZ | UTC timestamp of agreement |
+| ip_address | VARCHAR(45) | Client IP (supports IPv6) |
+| user_agent | TEXT | Browser/client user agent |
+| terms_version | VARCHAR | Version string (e.g., v2026-01-03) |
+| terms_url | VARCHAR | URL path to PDF |
+| terms_content_hash | VARCHAR(64) | SHA-256 hash of PDF content |
+
+## Files
+
+| Path | Purpose |
+|------|---------|
+| `migrations/001_create_terms_agreements.sql` | Database table creation |
+| `data/terms-agreement.repository.ts` | Data access layer |
+| `domain/terms-agreement.types.ts` | TypeScript interfaces |
+| `domain/terms-config.ts` | Static terms version and hash |
+| `index.ts` | Feature exports |
+
+## Invariants
+
+- Every user in `user_profiles` has exactly one record in `terms_agreements`
+- `agreed_at` is always stored in UTC
+- `terms_content_hash` matches SHA-256 of PDF at signup time

backend/src/features/terms-agreement/data/terms-agreement.repository.ts

@@ -0,0 +1,98 @@
+/**
+ * @ai-summary Terms agreement data access layer
+ * @ai-context Provides parameterized SQL queries for terms agreement operations
+ */
+
+import { Pool, PoolClient } from 'pg';
+import { TermsAgreement, CreateTermsAgreementRequest } from '../domain/terms-agreement.types';
+import { logger } from '../../../core/logging/logger';
+
+const TERMS_AGREEMENT_COLUMNS = `
+  id, user_id, agreed_at, ip_address, user_agent,
+  terms_version, terms_url, terms_content_hash,
+  created_at, updated_at
+`;
+
+export class TermsAgreementRepository {
+  constructor(private pool: Pool) {}
+
+  /**
+   * Create a new terms agreement record
+   * Can accept a PoolClient for transaction support
+   */
+  async create(
+    request: CreateTermsAgreementRequest,
+    client?: PoolClient
+  ): Promise<TermsAgreement> {
+    const query = `
+      INSERT INTO terms_agreements (
+        user_id, ip_address, user_agent,
+        terms_version, terms_url, terms_content_hash
+      )
+      VALUES ($1, $2, $3, $4, $5, $6)
+      RETURNING ${TERMS_AGREEMENT_COLUMNS}
+    `;
+
+    const values = [
+      request.userId,
+      request.ipAddress,
+      request.userAgent,
+      request.termsVersion,
+      request.termsUrl,
+      request.termsContentHash,
+    ];
+
+    try {
+      const executor = client || this.pool;
+      const result = await executor.query(query, values);
+
+      if (result.rows.length === 0) {
+        throw new Error('Failed to create terms agreement');
+      }
+
+      return this.mapRow(result.rows[0]);
+    } catch (error) {
+      logger.error('Error creating terms agreement', { error, userId: request.userId });
+      throw error;
+    }
+  }
+
+  /**
+   * Get terms agreement by user ID
+   */
+  async getByUserId(userId: string): Promise<TermsAgreement | null> {
+    const query = `
+      SELECT ${TERMS_AGREEMENT_COLUMNS}
+      FROM terms_agreements
+      WHERE user_id = $1
+      ORDER BY agreed_at DESC
+      LIMIT 1
+    `;
+
+    try {
+      const result = await this.pool.query(query, [userId]);
+      if (result.rows.length === 0) {
+        return null;
+      }
+      return this.mapRow(result.rows[0]);
+    } catch (error) {
+      logger.error('Error fetching terms agreement by user_id', { error, userId });
+      throw error;
+    }
+  }
+
+  private mapRow(row: any): TermsAgreement {
+    return {
+      id: row.id,
+      userId: row.user_id,
+      agreedAt: new Date(row.agreed_at),
+      ipAddress: row.ip_address,
+      userAgent: row.user_agent,
+      termsVersion: row.terms_version,
+      termsUrl: row.terms_url,
+      termsContentHash: row.terms_content_hash,
+      createdAt: new Date(row.created_at),
+      updatedAt: new Date(row.updated_at),
+    };
+  }
+}

backend/src/features/terms-agreement/domain/terms-agreement.types.ts

@@ -0,0 +1,25 @@
+/**
+ * @ai-summary TypeScript types for terms agreement feature
+ */
+
+export interface TermsAgreement {
+  id: string;
+  userId: string;
+  agreedAt: Date;
+  ipAddress: string;
+  userAgent: string;
+  termsVersion: string;
+  termsUrl: string;
+  termsContentHash: string;
+  createdAt: Date;
+  updatedAt: Date;
+}
+
+export interface CreateTermsAgreementRequest {
+  userId: string;
+  ipAddress: string;
+  userAgent: string;
+  termsVersion: string;
+  termsUrl: string;
+  termsContentHash: string;
+}

backend/src/features/terms-agreement/domain/terms-config.ts

@@ -0,0 +1,63 @@
+/**
+ * @ai-summary Terms & Conditions configuration
+ * @ai-context Static configuration for current T&C version, computed once at startup
+ */
+
+import { createHash } from 'crypto';
+import { readFileSync, existsSync } from 'fs';
+import { join } from 'path';
+import { logger } from '../../../core/logging/logger';
+
+// Current terms version and URL (update when PDF changes)
+const TERMS_VERSION = 'v2026-01-03';
+const TERMS_URL = '/docs/v2026-01-03.pdf';
+
+// Compute hash once at module load (startup)
+let termsContentHash: string | null = null;
+
+function computeTermsHash(): string {
+  if (termsContentHash) {
+    return termsContentHash;
+  }
+
+  // In production, PDF is served by frontend; backend may not have access
+  // For development, try to read from frontend/public/docs
+  const possiblePaths = [
+    join(__dirname, '../../../../../frontend/public/docs/v2026-01-03.pdf'),
+    join(process.cwd(), 'frontend/public/docs/v2026-01-03.pdf'),
+  ];
+
+  for (const pdfPath of possiblePaths) {
+    if (existsSync(pdfPath)) {
+      try {
+        const pdfContent = readFileSync(pdfPath);
+        termsContentHash = createHash('sha256').update(pdfContent).digest('hex');
+        logger.info('Terms content hash computed', {
+          version: TERMS_VERSION,
+          hash: termsContentHash.substring(0, 16) + '...'
+        });
+        return termsContentHash;
+      } catch (error) {
+        logger.warn('Failed to read terms PDF for hashing', { path: pdfPath, error });
+      }
+    }
+  }
+
+  // Fallback: use a placeholder hash (should be updated in production)
+  // In production, this should be pre-computed and set as an environment variable
+  termsContentHash = process.env['TERMS_CONTENT_HASH'] ||
+    'placeholder-hash-update-in-production';
+
+  logger.warn('Using fallback terms hash', {
+    hash: termsContentHash.substring(0, 16) + '...',
+    reason: 'PDF not found in development paths'
+  });
+
+  return termsContentHash;
+}
+
+export const termsConfig = {
+  version: TERMS_VERSION,
+  url: TERMS_URL,
+  getContentHash: computeTermsHash,
+};

backend/src/features/terms-agreement/index.ts

@@ -0,0 +1,6 @@
+/**
+ * @ai-summary Terms agreement feature exports
+ */
+
+export { TermsAgreementRepository } from './data/terms-agreement.repository';
+export { TermsAgreement, CreateTermsAgreementRequest } from './domain/terms-agreement.types';

backend/src/features/terms-agreement/migrations/001_create_terms_agreements.sql

@@ -0,0 +1,33 @@
+-- Terms Agreements Table
+-- Stores legal audit trail for Terms & Conditions acceptance at signup
+
+CREATE TABLE IF NOT EXISTS terms_agreements (
+  id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
+  user_id VARCHAR(255) NOT NULL,
+  agreed_at TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  ip_address VARCHAR(45) NOT NULL,
+  user_agent TEXT NOT NULL,
+  terms_version VARCHAR(50) NOT NULL,
+  terms_url VARCHAR(255) NOT NULL,
+  terms_content_hash VARCHAR(64) NOT NULL,
+  created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP,
+  updated_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
+);
+
+-- Index for user lookup
+CREATE INDEX IF NOT EXISTS idx_terms_agreements_user_id ON terms_agreements(user_id);
+
+-- Trigger for updated_at
+CREATE OR REPLACE FUNCTION update_terms_agreements_updated_at()
+RETURNS TRIGGER AS $$
+BEGIN
+  NEW.updated_at = CURRENT_TIMESTAMP;
+  RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+DROP TRIGGER IF EXISTS terms_agreements_updated_at ON terms_agreements;
+CREATE TRIGGER terms_agreements_updated_at
+  BEFORE UPDATE ON terms_agreements
+  FOR EACH ROW
+  EXECUTE FUNCTION update_terms_agreements_updated_at();