feat: add mosaic gateway CLI commands and admin token auth

Gateway daemon lifecycle management via the Mosaic CLI:
- install, start, stop, restart, status, config, logs, uninstall
- Admin API token auth (Bearer tokens) alongside existing session auth
- Bootstrap endpoint for first-user setup (POST /api/bootstrap/setup)
- admin_tokens table in DB schema with SHA-256 hashed tokens
- Gateway .env fallback loading from ~/.config/mosaic/gateway/.env
- CLI daemon management with PID file, log tailing, health checks

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

apps/gateway/src/admin/bootstrap.controller.ts

@@ -0,0 +1,101 @@
+import {
+  Body,
+  Controller,
+  ForbiddenException,
+  Get,
+  Inject,
+  InternalServerErrorException,
+  Post,
+} from '@nestjs/common';
+import { randomBytes, createHash } from 'node:crypto';
+import { count, eq, type Db, users as usersTable, adminTokens } from '@mosaic/db';
+import type { Auth } from '@mosaic/auth';
+import { v4 as uuid } from 'uuid';
+import { AUTH } from '../auth/auth.tokens.js';
+import { DB } from '../database/database.module.js';
+import type { BootstrapSetupDto, BootstrapStatusDto, BootstrapResultDto } from './bootstrap.dto.js';
+
+@Controller('api/bootstrap')
+export class BootstrapController {
+  constructor(
+    @Inject(AUTH) private readonly auth: Auth,
+    @Inject(DB) private readonly db: Db,
+  ) {}
+
+  @Get('status')
+  async status(): Promise<BootstrapStatusDto> {
+    const [result] = await this.db.select({ total: count() }).from(usersTable);
+    return { needsSetup: (result?.total ?? 0) === 0 };
+  }
+
+  @Post('setup')
+  async setup(@Body() dto: BootstrapSetupDto): Promise<BootstrapResultDto> {
+    // Only allow setup when zero users exist
+    const [result] = await this.db.select({ total: count() }).from(usersTable);
+    if ((result?.total ?? 0) > 0) {
+      throw new ForbiddenException('Setup already completed — users exist');
+    }
+
+    // Create admin user via BetterAuth API
+    const authApi = this.auth.api as unknown as {
+      createUser: (opts: {
+        body: { name: string; email: string; password: string; role?: string };
+      }) => Promise<{
+        user: { id: string; name: string; email: string };
+      }>;
+    };
+
+    const created = await authApi.createUser({
+      body: {
+        name: dto.name,
+        email: dto.email,
+        password: dto.password,
+        role: 'admin',
+      },
+    });
+
+    // Verify user was created
+    const [user] = await this.db
+      .select()
+      .from(usersTable)
+      .where(eq(usersTable.id, created.user.id))
+      .limit(1);
+
+    if (!user) throw new InternalServerErrorException('User created but not found');
+
+    // Ensure role is admin (createUser may not set it via BetterAuth)
+    if (user.role !== 'admin') {
+      await this.db.update(usersTable).set({ role: 'admin' }).where(eq(usersTable.id, user.id));
+    }
+
+    // Generate admin API token
+    const plaintext = randomBytes(32).toString('hex');
+    const tokenHash = createHash('sha256').update(plaintext).digest('hex');
+    const tokenId = uuid();
+
+    const [token] = await this.db
+      .insert(adminTokens)
+      .values({
+        id: tokenId,
+        userId: user.id,
+        tokenHash,
+        label: 'Initial setup token',
+        scope: 'admin',
+      })
+      .returning();
+
+    return {
+      user: {
+        id: user.id,
+        name: user.name,
+        email: user.email,
+        role: 'admin',
+      },
+      token: {
+        id: token!.id,
+        plaintext,
+        label: token!.label,
+      },
+    };
+  }
+}