feat: SaaS onboarding, Stripe billing, MFA, SSO, passkeys, refresh tokens

Complete SaaS self-service onboarding sprint:

- Stripe-powered signup flow: pricing page → checkout → provisioning → activation
- Refresh token infrastructure: 1h access tokens + 30-day httpOnly cookie refresh
- TOTP MFA with QR setup, recovery codes, and login challenge flow
- Google + Azure AD SSO (conditional on env vars) with account linking
- WebAuthn passkey registration and passwordless login
- Guided onboarding checklist with server-side progress tracking
- Stubbed email service (console + DB logging, ready for real provider)
- Settings page with tabbed security settings (MFA, passkeys, linked accounts)
- Login page enhanced with MFA verification, SSO buttons, passkey login
- Database migration 015 with all new tables and columns
- Version bump to 2026.03.17

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

backend/src/modules/auth/passkey.controller.ts

@@ -0,0 +1,112 @@
+import {
+  Controller,
+  Post,
+  Get,
+  Delete,
+  Param,
+  Body,
+  UseGuards,
+  Request,
+  Res,
+  BadRequestException,
+} from '@nestjs/common';
+import { ApiTags, ApiOperation, ApiBearerAuth } from '@nestjs/swagger';
+import { Throttle } from '@nestjs/throttler';
+import { Response } from 'express';
+import { PasskeyService } from './passkey.service';
+import { AuthService } from './auth.service';
+import { UsersService } from '../users/users.service';
+import { JwtAuthGuard } from './guards/jwt-auth.guard';
+import { AllowViewer } from '../../common/decorators/allow-viewer.decorator';
+
+const COOKIE_NAME = 'ledgeriq_rt';
+const isProduction = process.env.NODE_ENV === 'production';
+
+@ApiTags('auth')
+@Controller('auth/passkeys')
+export class PasskeyController {
+  constructor(
+    private passkeyService: PasskeyService,
+    private authService: AuthService,
+    private usersService: UsersService,
+  ) {}
+
+  @Post('register-options')
+  @ApiOperation({ summary: 'Get passkey registration options' })
+  @ApiBearerAuth()
+  @UseGuards(JwtAuthGuard)
+  async getRegistrationOptions(@Request() req: any) {
+    return this.passkeyService.generateRegistrationOptions(req.user.sub);
+  }
+
+  @Post('register')
+  @ApiOperation({ summary: 'Register a new passkey' })
+  @ApiBearerAuth()
+  @UseGuards(JwtAuthGuard)
+  async register(
+    @Request() req: any,
+    @Body() body: { response: any; deviceName?: string },
+  ) {
+    if (!body.response) throw new BadRequestException('Attestation response required');
+    return this.passkeyService.verifyRegistration(req.user.sub, body.response, body.deviceName);
+  }
+
+  @Post('login-options')
+  @ApiOperation({ summary: 'Get passkey login options' })
+  @Throttle({ default: { limit: 10, ttl: 60000 } })
+  async getLoginOptions(@Body() body: { email?: string }) {
+    return this.passkeyService.generateAuthenticationOptions(body.email);
+  }
+
+  @Post('login')
+  @ApiOperation({ summary: 'Authenticate with passkey' })
+  @Throttle({ default: { limit: 5, ttl: 60000 } })
+  async login(
+    @Body() body: { response: any; challenge: string },
+    @Res({ passthrough: true }) res: Response,
+  ) {
+    if (!body.response || !body.challenge) {
+      throw new BadRequestException('Assertion response and challenge required');
+    }
+
+    const { userId } = await this.passkeyService.verifyAuthentication(body.response, body.challenge);
+
+    // Get user with orgs and generate session
+    const user = await this.usersService.findByIdWithOrgs(userId);
+    if (!user) throw new BadRequestException('User not found');
+
+    await this.usersService.updateLastLogin(userId);
+    const result = await this.authService.generateTokenResponse(user);
+
+    if (result.refreshToken) {
+      res.cookie(COOKIE_NAME, result.refreshToken, {
+        httpOnly: true,
+        secure: isProduction,
+        sameSite: 'strict',
+        path: '/api/auth',
+        maxAge: 30 * 24 * 60 * 60 * 1000,
+      });
+    }
+
+    const { refreshToken: _rt, ...response } = result;
+    return response;
+  }
+
+  @Get()
+  @ApiOperation({ summary: 'List registered passkeys' })
+  @ApiBearerAuth()
+  @UseGuards(JwtAuthGuard)
+  @AllowViewer()
+  async list(@Request() req: any) {
+    return this.passkeyService.listPasskeys(req.user.sub);
+  }
+
+  @Delete(':id')
+  @ApiOperation({ summary: 'Remove a passkey' })
+  @ApiBearerAuth()
+  @UseGuards(JwtAuthGuard)
+  async remove(@Request() req: any, @Param('id') passkeyId: string) {
+    await this.passkeyService.removePasskey(req.user.sub, passkeyId);
+    return { success: true };
+  }
+}