feat(storage): wire MinIO/S3 document upload & download into the API + web

The schema has carried `storageKey` pointers and the migration has written
blobs to MinIO since day one, but the API had no S3 client — documents could
only be deleted, never uploaded or retrieved. This adds the missing wiring.

API
- StorageModule/StorageService (@aws-sdk/client-s3, path-style for MinIO):
  put/getStream/delete, best-effort bucket ensure on boot, gracefully disabled
  when S3 env is absent (ServiceUnavailable on use).
- Reads S3_ENDPOINT/S3_BUCKET + S3_ACCESS_KEY/S3_SECRET_KEY, falling back to
  MINIO_ROOT_USER/MINIO_ROOT_PASSWORD so one credential set drives both the
  migration and the API.
- Property service documents: POST :id/documents (multipart), GET
  :id/documents/:childId/download (streamed), delete now also drops the blob.
- Policy documents: same upload/download/delete (previously had none).
- Keys stay under the service/<id>/… and policy/<id>/… prefixes the migration
  established.

Web
- api.ts: shared uploadFile() helper (uploadIngest refactored onto it),
  upload/download/remove helpers for property & policy documents.
- Servicios, polizas, clientes detail pages: real Descargar links and an
  upload control (gated by policy:update / property:update) replacing the
  "storage pending" notes.

Infra
- docker-compose: minio service (9000/9001, healthcheck, named volume) + S3
  env wired into the api service.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/api/src/storage/storage.service.ts

@@ -0,0 +1,122 @@
+import {
+  Injectable,
+  Logger,
+  OnModuleInit,
+  ServiceUnavailableException,
+} from "@nestjs/common";
+import { ConfigService } from "@nestjs/config";
+import {
+  CreateBucketCommand,
+  DeleteObjectCommand,
+  GetObjectCommand,
+  HeadBucketCommand,
+  PutObjectCommand,
+  S3Client,
+} from "@aws-sdk/client-s3";
+import type { Readable } from "node:stream";
+
+/**
+ * S3 / MinIO object storage for document blobs. MySQL keeps only the pointer
+ * (`storageKey`) + metadata; the bytes live here. Same bucket the migration's
+ * `blob_extract.py` writes to, so keys stay under the `service/…` and
+ * `policy/…` prefixes it established.
+ *
+ * Env (see deploy/.env.dev): S3_ENDPOINT, S3_BUCKET, and creds — S3_ACCESS_KEY
+ * / S3_SECRET_KEY, falling back to MINIO_ROOT_USER / MINIO_ROOT_PASSWORD so a
+ * single MinIO credential set drives both the migration and the API.
+ */
+@Injectable()
+export class StorageService implements OnModuleInit {
+  private readonly logger = new Logger(StorageService.name);
+  private readonly client: S3Client | null;
+  readonly bucket: string;
+
+  constructor(config: ConfigService) {
+    const endpoint = config.get<string>("S3_ENDPOINT");
+    this.bucket = config.get<string>("S3_BUCKET") ?? "jorgecuadros-documents";
+    const accessKeyId =
+      config.get<string>("S3_ACCESS_KEY") ?? config.get<string>("MINIO_ROOT_USER");
+    const secretAccessKey =
+      config.get<string>("S3_SECRET_KEY") ?? config.get<string>("MINIO_ROOT_PASSWORD");
+
+    if (!endpoint || !accessKeyId || !secretAccessKey) {
+      this.logger.warn(
+        "Object storage not configured (missing S3_ENDPOINT / credentials); " +
+          "document upload & download are disabled.",
+      );
+      this.client = null;
+      return;
+    }
+
+    this.client = new S3Client({
+      endpoint,
+      region: config.get<string>("S3_REGION") ?? "us-east-1",
+      credentials: { accessKeyId, secretAccessKey },
+      forcePathStyle: true, // MinIO needs path-style addressing
+    });
+  }
+
+  /** Best-effort bucket check on boot; never blocks API startup. */
+  async onModuleInit() {
+    if (!this.client) return;
+    try {
+      await this.client.send(new HeadBucketCommand({ Bucket: this.bucket }));
+    } catch {
+      try {
+        await this.client.send(new CreateBucketCommand({ Bucket: this.bucket }));
+        this.logger.log(`Created bucket "${this.bucket}".`);
+      } catch (err) {
+        this.logger.warn(
+          `Could not verify/create bucket "${this.bucket}": ${(err as Error).message}`,
+        );
+      }
+    }
+  }
+
+  private require(): S3Client {
+    if (!this.client) {
+      throw new ServiceUnavailableException(
+        "El almacenamiento de documentos no está configurado.",
+      );
+    }
+    return this.client;
+  }
+
+  async put(key: string, body: Buffer, contentType?: string): Promise<void> {
+    await this.require().send(
+      new PutObjectCommand({
+        Bucket: this.bucket,
+        Key: key,
+        Body: body,
+        ContentType: contentType,
+      }),
+    );
+  }
+
+  async getStream(key: string): Promise<{
+    stream: Readable;
+    contentType?: string;
+    contentLength?: number;
+  }> {
+    const out = await this.require().send(
+      new GetObjectCommand({ Bucket: this.bucket, Key: key }),
+    );
+    return {
+      stream: out.Body as Readable,
+      contentType: out.ContentType,
+      contentLength: out.ContentLength,
+    };
+  }
+
+  /** Best-effort blob delete; a missing object is not an error. */
+  async delete(key: string): Promise<void> {
+    if (!this.client) return;
+    try {
+      await this.client.send(
+        new DeleteObjectCommand({ Bucket: this.bucket, Key: key }),
+      );
+    } catch (err) {
+      this.logger.warn(`Failed to delete blob "${key}": ${(err as Error).message}`);
+    }
+  }
+}