fix: resolve K-1 PDF upload ENOENT and controller route prefix issues

- Register MulterModule with disk storage in K1ImportModule so FileInterceptor
  writes uploaded files to disk (sets file.filename and file.path)
- Make UploadService.createDocument robust for both disk and memory storage
  by generating filename and writing buffer to disk when file.filename is unset
- Fix reprocess method to join relative filePath with uploadDir for absolute path
- Remove duplicate 'api/v1' prefix from K1ImportController and CellMappingController
  (NestJS global prefix + URI versioning already adds /api/v1/)

apps/api/src/app/cell-mapping/cell-mapping.controller.ts

@@ -14,7 +14,7 @@ import { AuthGuard } from '@nestjs/passport';
 
 import { CellMappingService } from './cell-mapping.service';
 
-@Controller('api/v1/cell-mapping')
+@Controller('cell-mapping')
 export class CellMappingController {
   public constructor(
     private readonly cellMappingService: CellMappingService

apps/api/src/app/k1-import/k1-import.controller.ts

@@ -26,7 +26,7 @@ import { ConfirmK1Dto } from './dto/confirm-k1.dto';
 import { VerifyK1Dto } from './dto/verify-k1.dto';
 import { K1ImportService } from './k1-import.service';
 
-@Controller('api/v1/k1-import')
+@Controller('k1-import')
 export class K1ImportController {
   public constructor(
     private readonly k1ImportService: K1ImportService,

apps/api/src/app/k1-import/k1-import.module.ts

@@ -2,6 +2,11 @@ import { ConfigurationModule } from '@ghostfolio/api/services/configuration/conf
 import { PrismaModule } from '@ghostfolio/api/services/prisma/prisma.module';
 
 import { Module } from '@nestjs/common';
+import { MulterModule } from '@nestjs/platform-express';
+import { diskStorage } from 'multer';
+import { existsSync, mkdirSync } from 'node:fs';
+import { join } from 'node:path';
+import { v4 as uuidv4 } from 'uuid';
 
 import { CellMappingModule } from '../cell-mapping/cell-mapping.module';
 import { UploadModule } from '../upload/upload.module';
@@ -15,10 +20,40 @@ import { AzureExtractor } from './extractors/azure-extractor';
 import { PdfParseExtractor } from './extractors/pdf-parse-extractor';
 import { TesseractExtractor } from './extractors/tesseract-extractor';
 
+const uploadDir = process.env.UPLOAD_DIR || join(process.cwd(), 'uploads');
+
 @Module({
   controllers: [K1ImportController],
   exports: [K1ImportService],
-  imports: [CellMappingModule, ConfigurationModule, PrismaModule, UploadModule],
+  imports: [
+    CellMappingModule,
+    ConfigurationModule,
+    MulterModule.register({
+      limits: {
+        fileSize: 25 * 1024 * 1024 // 25 MB
+      },
+      storage: diskStorage({
+        destination: (_req, _file, cb) => {
+          const now = new Date();
+          const yearDir = now.getFullYear().toString();
+          const monthDir = (now.getMonth() + 1).toString().padStart(2, '0');
+          const subDir = join(uploadDir, yearDir, monthDir);
+
+          if (!existsSync(subDir)) {
+            mkdirSync(subDir, { recursive: true });
+          }
+
+          cb(null, subDir);
+        },
+        filename: (_req, file, cb) => {
+          const ext = file.originalname.split('.').pop();
+          cb(null, `${uuidv4()}.${ext}`);
+        }
+      })
+    }),
+    PrismaModule,
+    UploadModule
+  ],
   providers: [
     AzureExtractor,
     K1AggregationService,

apps/api/src/app/k1-import/k1-import.service.ts

@@ -476,16 +476,18 @@ export class K1ImportService {
 
     // Read file from disk and run extraction asynchronously
     const fs = await import('fs/promises');
-    const filePath = (document as any).url || (document as any).filePath;
+    const relativePath = (document as any).filePath;
 
-    if (!filePath) {
+    if (!relativePath) {
       throw new HttpException(
         'Cannot determine file path for stored document',
         StatusCodes.INTERNAL_SERVER_ERROR
       );
     }
 
-    const fileBuffer = await fs.readFile(filePath);
+    const uploadDir = this.uploadService.getUploadDir();
+    const fullPath = join(uploadDir, relativePath);
+    const fileBuffer = await fs.readFile(fullPath);
     const file = {
       buffer: fileBuffer,
       originalname: originalSession.fileName,

apps/api/src/app/upload/upload.service.ts

@@ -4,8 +4,9 @@ import { HttpException, Injectable } from '@nestjs/common';
 import { DocumentType } from '@prisma/client';
 import { StatusCodes, getReasonPhrase } from 'http-status-codes';
 import { createReadStream, existsSync } from 'node:fs';
-import { mkdir } from 'node:fs/promises';
+import { mkdir, writeFile } from 'node:fs/promises';
 import { join } from 'node:path';
+import { v4 as uuidv4 } from 'uuid';
 
 @Injectable()
 export class UploadService {
@@ -51,7 +52,19 @@ export class UploadService {
       await mkdir(subDir, { recursive: true });
     }
 
-    const relativePath = `${yearDir}/${monthDir}/${file.filename}`;
+    // Support both disk storage (file.filename set by multer) and memory storage (file.buffer)
+    let filename = file.filename;
+
+    if (!filename) {
+      const ext = (file.originalname || 'file').split('.').pop();
+      filename = `${uuidv4()}.${ext}`;
+
+      if (file.buffer) {
+        await writeFile(join(subDir, filename), file.buffer);
+      }
+    }
+
+    const relativePath = `/${yearDir}/${monthDir}/${filename}`;
 
     return this.prismaService.document.create({
       data: {