feat(auth): add GET /keys to list available key identifiers

src/auth/auth.controller.ts

@@ -1,4 +1,4 @@
-import { Body, Controller, Post } from '@nestjs/common';
+import { Body, Controller, Get, Post } from '@nestjs/common';
 import { ApiOperation, ApiResponse, ApiTags } from '@nestjs/swagger';
 import { AuthService } from './auth.service';
 import { LoginDto } from './dto/login.dto';
@@ -8,6 +8,13 @@ import { LoginDto } from './dto/login.dto';
 export class AuthController {
   constructor(private readonly authService: AuthService) {}
 
+  @Get('keys')
+  @ApiOperation({ summary: 'List available key identifiers from the keys directory' })
+  @ApiResponse({ status: 200, description: 'List of key names', schema: { properties: { keys: { type: 'array', items: { type: 'string' } } } } })
+  listKeys(): { keys: string[] } {
+    return { keys: this.authService.listKeys() };
+  }
+
   @Post('login')
   @ApiOperation({ summary: 'Log in using a file key and return the session token' })
   @ApiResponse({ status: 201, description: 'Login successful', schema: { properties: { token: { type: 'string' }, sessionName: { type: 'string' } } } })

src/auth/auth.service.ts

@@ -40,6 +40,13 @@ export class AuthService {
     );
   }
 
+  listKeys(): string[] {
+    if (!fs.existsSync(this.keysDir)) return [];
+    return fs.readdirSync(this.keysDir)
+      .filter(f => f.endsWith('.json'))
+      .map(f => path.basename(f, '.json'));
+  }
+
   async login(keyId: string, sessionName?: string): Promise<{ token: string; sessionName: string }> {
     const resolvedSession = sessionName ?? crypto.randomUUID();