chore(deps): update vitest monorepo to v4.1.8

Reviewed-on: #37

lib/Controllers/DefaultController.php

@@ -13,6 +13,7 @@ use InvalidArgumentException;
 use KTXC\Http\Response\JsonResponse;
 use KTXC\Http\Response\Response;
 use KTXC\Http\Response\StreamedNdJsonResponse;
+use KTXC\Http\Response\StreamedResponse;
 use KTXC\SessionIdentity;
 use KTXC\SessionTenant;
 use KTXF\Controller\ControllerAbstract;
@@ -31,12 +32,6 @@ use KTXM\MailManager\Manager;
 use Psr\Log\LoggerInterface;
 use Throwable;
 
-/**
- * Default Controller - Unified Mail API
- * 
- * Handles all mail operations in JMAP-style API pattern.
- * Supports both single operations and batches with result references.
- */
 class DefaultController extends ControllerAbstract {
 
     private const ERR_MISSING_PROVIDER = 'Missing parameter: provider';
@@ -168,6 +163,7 @@ class DefaultController extends ControllerAbstract {
             'entity.move' => $this->entityMove($tenantId, $userId, $data),
             'entity.copy' => throw new InvalidArgumentException('Operation not implemented: ' . $operation),
             'entity.transmit' => $this->entityTransmit($tenantId, $userId, $data),
+            'entity.download' => $this->entityDownload($tenantId, $userId, $data),
             
             default => throw new InvalidArgumentException(self::ERR_INVALID_OPERATION . $operation)
         };
@@ -558,14 +554,14 @@ class DefaultController extends ControllerAbstract {
         
         if (is_bool($result)) {
             return [
-                'outcome' => 'deleted'
+                'disposition' => 'deleted'
             ];
         }
 
         if ($result instanceof JsonSerializable) {
             return [
-                'outcome' => 'moved',
+                'disposition' => 'moved',
-                'data' => $result
+                'mutation' => $result
             ];
         }
 
@@ -773,21 +769,21 @@ class DefaultController extends ControllerAbstract {
     }
 
     private function entityDelete(string $tenantId, string $userId, array $data): mixed {
-        if (!isset($data['sources'])) {
+        if (!isset($data['targets'])) {
-            throw new InvalidArgumentException(self::ERR_MISSING_SOURCES);
+            throw new InvalidArgumentException(self::ERR_MISSING_TARGETS);
         }
-        if (!is_array($data['sources'])) {
+        if (!is_array($data['targets'])) {
-            throw new InvalidArgumentException(self::ERR_INVALID_SOURCES);
+            throw new InvalidArgumentException(self::ERR_INVALID_TARGETS);
         }
 
-        $sources = ResourceIdentifiers::fromArray($data['sources']);
+        $targets = ResourceIdentifiers::fromArray($data['targets']);
-        foreach ($sources as $source) {
+        foreach ($targets as $target) {
-            if (!$source instanceof EntityIdentifier) {
+            if (!$target instanceof EntityIdentifier) {
-                throw new InvalidArgumentException('Invalid parameter: sources must contain provider:service:collection:entity identifiers');
+                throw new InvalidArgumentException('Invalid parameter: targets must contain provider:service:collection:entity identifiers');
             }
         }
         
-        return $this->mailManager->entityDelete($tenantId, $userId, ...$sources->all());
+        return $this->mailManager->entityDelete($tenantId, $userId, ...$targets->all());
     }
 
     private function entityPatch(string $tenantId, string $userId, array $data): mixed {
@@ -868,4 +864,46 @@ class DefaultController extends ControllerAbstract {
         return ['jobId' => $jobId];
     }
 
+    private function entityDownload(string $tenantId, string $userId, array $data): mixed {
+        if (!isset($data['target'])) {
+            throw new InvalidArgumentException(self::ERR_MISSING_TARGET);
+        }
+        if (!is_string($data['target'])) {
+            throw new InvalidArgumentException(self::ERR_INVALID_IDENTIFIER);
+        }
+
+        // 'part' is optional — null means full RFC 822 message download
+        $part = isset($data['part']) && is_array($data['part']) ? $data['part'] : null;
+
+        $target = ResourceIdentifier::fromString($data['target']);
+        $logger = $this->logger;
+
+        $result = $this->mailManager->entityDownload($tenantId, $userId, $target, $part);
+
+        $filename       = $result->filename();
+        $asciiFilename  = preg_replace('/[^\x20-\x7E]|[\\\\"]/', '_', $filename);
+        $encodedFilename = rawurlencode($filename);
+        $disposition    = sprintf(
+            'attachment; filename="%s"; filename*=UTF-8\'\'%s',
+            $asciiFilename,
+            $encodedFilename,
+        );
+
+        $responseGenerator = (static function () use ($result, $logger): \Generator {
+            try {
+                yield from $result->stream();
+            } catch (\Throwable $t) {
+                $logger->error('Error streaming entity download', ['exception' => $t]);
+                // Headers already sent — cannot change status code; stop output cleanly
+            }
+        })();
+
+        return new StreamedResponse($responseGenerator, 200, [
+            'Content-Disposition'       => $disposition,
+            'Content-Type'              => $result->mimeType(),
+            'Content-Transfer-Encoding' => 'binary',
+            'Cache-Control'             => 'no-store',
+        ]);
+    }
+
 }

lib/Manager.php

@@ -20,6 +20,7 @@ use KTXF\Mail\Service\ServiceCollectionMutableInterface;
 use KTXF\Mail\Service\ServiceConfigurableInterface;
 use KTXF\Mail\Service\ServiceEntityMutableInterface;
 use KTXF\Mail\Service\ServiceMutableInterface;
+use KTXF\Resource\BinaryResource;
 use KTXF\Resource\Filter\IFilter;
 use KTXF\Resource\Identifier\CollectionIdentifier;
 use KTXF\Resource\Identifier\EntityIdentifier;
@@ -951,6 +952,13 @@ class Manager {
         }
     }
 
+    public function entityDownload(string $tenantId, string $userId, EntityIdentifier $targetEntity, array|null $targetPart): BinaryResource {
+        // retrieve service
+        $service = $this->serviceFetch($tenantId, $userId, $targetEntity->provider(), $targetEntity->service());
+        // download entity
+        return $service->entityDownload($targetEntity, $targetPart);
+    }
+
     /**
      * Check if messages exist
      *
@@ -1294,5 +1302,4 @@ class Manager {
         return $operationOutcome;
     }
 
-
 }

package-lock.json

@@ -592,14 +592,14 @@
       }
     },
     "node_modules/@vitest/coverage-v8": {
-      "version": "4.1.7",
+      "version": "4.1.8",
-      "resolved": "https://registry.npmjs.org/@vitest/coverage-v8/-/coverage-v8-4.1.7.tgz",
+      "resolved": "https://registry.npmjs.org/@vitest/coverage-v8/-/coverage-v8-4.1.8.tgz",
-      "integrity": "sha512-qsYPeXc5Q9dFLd1i8Ap+Bx8sQgcp+rFVQo4R0dDsWNBzl26ldVF1qOO+RL24K7FDrR6pA+50XedRLSoSG24bVQ==",
+      "integrity": "sha512-lt3kovsyHwYe00wq4D1ti0Z974fWj4NLp6siqiyEufUpyFwK9Yhi7rBhac9JL5aA0zoMrJqc4vYPZRUnI7l7nw==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
         "@bcoe/v8-coverage": "^1.0.2",
-        "@vitest/utils": "4.1.7",
+        "@vitest/utils": "4.1.8",
         "ast-v8-to-istanbul": "^1.0.0",
         "istanbul-lib-coverage": "^3.2.2",
         "istanbul-lib-report": "^3.0.1",
@@ -613,8 +613,8 @@
         "url": "https://opencollective.com/vitest"
       },
       "peerDependencies": {
-        "@vitest/browser": "4.1.7",
+        "@vitest/browser": "4.1.8",
-        "vitest": "4.1.7"
+        "vitest": "4.1.8"
       },
       "peerDependenciesMeta": {
         "@vitest/browser": {
@@ -623,17 +623,17 @@
       }
     },
     "node_modules/@vitest/expect": {
-      "version": "4.1.7",
+      "version": "4.1.8",
-      "resolved": "https://registry.npmjs.org/@vitest/expect/-/expect-4.1.7.tgz",
+      "resolved": "https://registry.npmjs.org/@vitest/expect/-/expect-4.1.8.tgz",
-      "integrity": "sha512-1R+tw0ortHEbZDGMymm+pN7/AFQ/RkFFdtd7EN+VBpynKmLbP8A3rpEXdshBJ7+8hQ9zBJh/i1s0yKNtxAnU7w==",
+      "integrity": "sha512-h3nDO677RDLEGlBxyQ5CW8RlMThSKSRLUePLOx09gNIWRL40edgA1GCZSZgf1W55MFAG6/Sw14KeaAnqv0NKdQ==",
       "dev": true,
       "license": "MIT",
       "peer": true,
       "dependencies": {
         "@standard-schema/spec": "^1.1.0",
         "@types/chai": "^5.2.2",
-        "@vitest/spy": "4.1.7",
+        "@vitest/spy": "4.1.8",
-        "@vitest/utils": "4.1.7",
+        "@vitest/utils": "4.1.8",
         "chai": "^6.2.2",
         "tinyrainbow": "^3.1.0"
       },
@@ -642,14 +642,14 @@
       }
     },
     "node_modules/@vitest/mocker": {
-      "version": "4.1.7",
+      "version": "4.1.8",
-      "resolved": "https://registry.npmjs.org/@vitest/mocker/-/mocker-4.1.7.tgz",
+      "resolved": "https://registry.npmjs.org/@vitest/mocker/-/mocker-4.1.8.tgz",
-      "integrity": "sha512-vY7nuamKgfvpA1Koa3oYIw/k7D6kZnpGyNMZW8loow2bsBYla1TFdqTaXncWdRn4pgwNs+90RhnXhJScDwQeJA==",
+      "integrity": "sha512-LEiN/xe4OSIbKe9HQIp5OC24agGD9J5CnmMgsLohVVoOPWL9a2sBoR6VBx43jQZb7Kr1l4RCuyCJzcAa0+dojw==",
       "dev": true,
       "license": "MIT",
       "peer": true,
       "dependencies": {
-        "@vitest/spy": "4.1.7",
+        "@vitest/spy": "4.1.8",
         "estree-walker": "^3.0.3",
         "magic-string": "^0.30.21"
       },
@@ -681,9 +681,9 @@
       }
     },
     "node_modules/@vitest/pretty-format": {
-      "version": "4.1.7",
+      "version": "4.1.8",
-      "resolved": "https://registry.npmjs.org/@vitest/pretty-format/-/pretty-format-4.1.7.tgz",
+      "resolved": "https://registry.npmjs.org/@vitest/pretty-format/-/pretty-format-4.1.8.tgz",
-      "integrity": "sha512-umgCarTOYQWIaDMvGDRZij+6b9oVeLIyJzfN+AS88e0ZOU3QTgNNSTtjQOpcvWr3np1N0j4WgZj+sb3oYBDscw==",
+      "integrity": "sha512-9GasEBxpZ1VYIpqHf/0+YGg121uSNwCKOJqIrTwWP/TB7DmFCiaBpNl3aPZzoLWfWkuqhbH8vJIVobZkvdo2cA==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
@@ -694,14 +694,14 @@
       }
     },
     "node_modules/@vitest/runner": {
-      "version": "4.1.7",
+      "version": "4.1.8",
-      "resolved": "https://registry.npmjs.org/@vitest/runner/-/runner-4.1.7.tgz",
+      "resolved": "https://registry.npmjs.org/@vitest/runner/-/runner-4.1.8.tgz",
-      "integrity": "sha512-BapjmAQ2aI78WdMEfeUWivnfVzB+VPGwWRQcJE0OUq7qEeEcBsCSf+0T5iREBNE5nBb4wA5Ya0W6IA+sghdEFw==",
+      "integrity": "sha512-EmVxeBAfMJvycdjd6Hm+RbFBbA9fKvo0Kx37hNpBYoYeavH3RNsBXWDooR1mgD52dCrxIIuP7UotpfiwOikvcg==",
       "dev": true,
       "license": "MIT",
       "peer": true,
       "dependencies": {
-        "@vitest/utils": "4.1.7",
+        "@vitest/utils": "4.1.8",
         "pathe": "^2.0.3"
       },
       "funding": {
@@ -709,15 +709,15 @@
       }
     },
     "node_modules/@vitest/snapshot": {
-      "version": "4.1.7",
+      "version": "4.1.8",
-      "resolved": "https://registry.npmjs.org/@vitest/snapshot/-/snapshot-4.1.7.tgz",
+      "resolved": "https://registry.npmjs.org/@vitest/snapshot/-/snapshot-4.1.8.tgz",
-      "integrity": "sha512-ZacLzja+TmJeZ1h14xW2FB/WpeimUD3haBXQPyJqxvo8jQTmfeA8zv58mtjN2C7EHXZDYVcVYdYmAxjkWVvKCw==",
+      "integrity": "sha512-acfZboRmAIf05DEKcBQy33VXojFJjtUdLyo7oOmV9kebb2xdU01UknNiPuPZoJZQyO7DF0gZdTGTpeAzET9QPQ==",
       "dev": true,
       "license": "MIT",
       "peer": true,
       "dependencies": {
-        "@vitest/pretty-format": "4.1.7",
+        "@vitest/pretty-format": "4.1.8",
-        "@vitest/utils": "4.1.7",
+        "@vitest/utils": "4.1.8",
         "magic-string": "^0.30.21",
         "pathe": "^2.0.3"
       },
@@ -726,9 +726,9 @@
       }
     },
     "node_modules/@vitest/spy": {
-      "version": "4.1.7",
+      "version": "4.1.8",
-      "resolved": "https://registry.npmjs.org/@vitest/spy/-/spy-4.1.7.tgz",
+      "resolved": "https://registry.npmjs.org/@vitest/spy/-/spy-4.1.8.tgz",
-      "integrity": "sha512-kbkI5LMWakyuTIvs6fUJ5qdIVb1XVKsYJAT4OJ938cHMROYMSfmoQdZy0aaAnjbbc8F61vkoTqz/Az+/HiIu5Q==",
+      "integrity": "sha512-6EevtBp6OZOPF7bmz36HrGMeP3txgVSrgebWxHOafDXGkhIzfXK14f8KF6MuFfgXXUeHxmpD3BQxkV00/3s5mA==",
       "dev": true,
       "license": "MIT",
       "peer": true,
@@ -737,13 +737,13 @@
       }
     },
     "node_modules/@vitest/ui": {
-      "version": "4.1.7",
+      "version": "4.1.8",
-      "resolved": "https://registry.npmjs.org/@vitest/ui/-/ui-4.1.7.tgz",
+      "resolved": "https://registry.npmjs.org/@vitest/ui/-/ui-4.1.8.tgz",
-      "integrity": "sha512-TP6utB2yX6rsJNVRo2qAlsi48i1YwFTrLV2tnTtWqJaYX7m4lRCCLirZBjU6xC5m0RsPHr+L2+N+eIPhgEzFfw==",
+      "integrity": "sha512-RUS2ZU2TsduVrI+9c12uTNaKrNUTsm6yFt3fueEUB9iKvyC2UP83F+sqIz00HQIah4UOL1TMoDAki8K0NjGvsA==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
-        "@vitest/utils": "4.1.7",
+        "@vitest/utils": "4.1.8",
         "fflate": "^0.8.2",
         "flatted": "^3.4.2",
         "pathe": "^2.0.3",
@@ -755,17 +755,17 @@
         "url": "https://opencollective.com/vitest"
       },
       "peerDependencies": {
-        "vitest": "4.1.7"
+        "vitest": "4.1.8"
       }
     },
     "node_modules/@vitest/utils": {
-      "version": "4.1.7",
+      "version": "4.1.8",
-      "resolved": "https://registry.npmjs.org/@vitest/utils/-/utils-4.1.7.tgz",
+      "resolved": "https://registry.npmjs.org/@vitest/utils/-/utils-4.1.8.tgz",
-      "integrity": "sha512-T532WBu791cBxJlCl6SO+J14l81DQx6uQHm1bQbmCDY7nqlEIgkza/UFnSBNaUtSf41unldDFjdOBYEQC4b5Hw==",
+      "integrity": "sha512-uOJamYALNhfJ6iolExyQM40yIQwDqYnkKtQ5VCiSe17E33H0aQ/u+1GlRuz4LZBk6Mm3sg90G9hEbmEt37C1Zg==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
-        "@vitest/pretty-format": "4.1.7",
+        "@vitest/pretty-format": "4.1.8",
         "convert-source-map": "^2.0.0",
         "tinyrainbow": "^3.1.0"
       },
@@ -2255,20 +2255,20 @@
       }
     },
     "node_modules/vitest": {
-      "version": "4.1.7",
+      "version": "4.1.8",
-      "resolved": "https://registry.npmjs.org/vitest/-/vitest-4.1.7.tgz",
+      "resolved": "https://registry.npmjs.org/vitest/-/vitest-4.1.8.tgz",
-      "integrity": "sha512-flYyaFd2CgoCoU+0UKt3pxksgC+S02iTDN0n3LtqaMeXsI9SBcdNujc2k0DeFLzUn/0k538yNjOSdwgCqcrwJA==",
+      "integrity": "sha512-flY6ScbCIt9HThs+C5HS7jvGOB560DJtk/Z15IQROTA6zEy49Nh8T/dofWTQL+n3vswqn87sbJNiuqw1SDp5Ig==",
       "dev": true,
       "license": "MIT",
       "peer": true,
       "dependencies": {
-        "@vitest/expect": "4.1.7",
+        "@vitest/expect": "4.1.8",
-        "@vitest/mocker": "4.1.7",
+        "@vitest/mocker": "4.1.8",
-        "@vitest/pretty-format": "4.1.7",
+        "@vitest/pretty-format": "4.1.8",
-        "@vitest/runner": "4.1.7",
+        "@vitest/runner": "4.1.8",
-        "@vitest/snapshot": "4.1.7",
+        "@vitest/snapshot": "4.1.8",
-        "@vitest/spy": "4.1.7",
+        "@vitest/spy": "4.1.8",
-        "@vitest/utils": "4.1.7",
+        "@vitest/utils": "4.1.8",
         "es-module-lexer": "^2.0.0",
         "expect-type": "^1.3.0",
         "magic-string": "^0.30.21",
@@ -2296,12 +2296,12 @@
         "@edge-runtime/vm": "*",
         "@opentelemetry/api": "^1.9.0",
         "@types/node": "^20.0.0 || ^22.0.0 || >=24.0.0",
-        "@vitest/browser-playwright": "4.1.7",
+        "@vitest/browser-playwright": "4.1.8",
-        "@vitest/browser-preview": "4.1.7",
+        "@vitest/browser-preview": "4.1.8",
-        "@vitest/browser-webdriverio": "4.1.7",
+        "@vitest/browser-webdriverio": "4.1.8",
-        "@vitest/coverage-istanbul": "4.1.7",
+        "@vitest/coverage-istanbul": "4.1.8",
-        "@vitest/coverage-v8": "4.1.7",
+        "@vitest/coverage-v8": "4.1.8",
-        "@vitest/ui": "4.1.7",
+        "@vitest/ui": "4.1.8",
         "happy-dom": "*",
         "jsdom": "*",
         "vite": "^6.0.0 || ^7.0.0 || ^8.0.0"

src/services/entityService.ts

@@ -2,7 +2,7 @@
  * Entity management service
  */
 
-import { transceivePost, transceiveStream } from './transceive';
+import { transceivePost, transceiveStream, transceiveDownload } from './transceive';
 import type {
   EntityFetchRequest,
   EntityFetchResponse,
@@ -27,6 +27,7 @@ import type {
   EntityListBulkRequest,
   EntityPatchResponse,
   EntityPatchRequest,
+  EntityDownloadRequest,
 } from '../types/entity';
 import { useIntegrationStore } from '@KTXC/stores/integrationStore';
 import { EntityObject } from '../models';
@@ -110,7 +111,7 @@ export const entityService = {
     
     // Convert response to EntityObject instances
     const list: Record<string, EntityObject> = {};
-    Object.entries(response).forEach(([identifier, entity]) => {
+    Object.entries(response).forEach(([, entity]) => {
       list[entity.identifier] = createEntityObject(entity);
     });
     
@@ -216,6 +217,16 @@ export const entityService = {
   async transmit(request: EntityTransmitRequest): Promise<EntityTransmitResponse> {
     return await transceivePost<EntityTransmitRequest, EntityTransmitResponse>('entity.transmit', request);
   },
+
+  /**
+   * Submit a browser-native attachment download request.
+   *
+   * The backend download endpoint is expected to honor the supplied selector
+   * and respond with an attachment payload rather than JSON.
+   */
+  download(request: EntityDownloadRequest): { transaction: string } {
+    return transceiveDownload<EntityDownloadRequest>('entity.download', request);
+  },
 };
 
 export default entityService;

src/services/transceive.ts

@@ -141,3 +141,84 @@ export async function transceiveStream<TRequest, TData>(
 
   return { total };
 }
+
+/**
+ * Submit a browser-native file download request via a top-level form POST.
+ *
+ * This avoids buffering the response body in application-managed JavaScript
+ * memory. The backend is expected to accept form fields where `data` contains
+ * the serialized operation payload and to return an attachment response.
+ */
+export function transceiveDownload<TRequest>(
+  operation: string,
+  data: TRequest,
+  user?: string,
+): { transaction: string } {
+  if (typeof document === 'undefined' || typeof window === 'undefined') {
+    throw new Error('Browser window is not available for download submission');
+  }
+
+  const request: ApiRequest<TRequest> = {
+    version: API_VERSION,
+    transaction: generateTransactionId(),
+    operation,
+    data,
+    user,
+  };
+
+  const form = document.createElement('form');
+  form.method = 'POST';
+  form.action = API_URL;
+  form.target = '_blank';
+  form.style.display = 'none';
+
+  appendHiddenField(form, 'version', String(request.version));
+  appendHiddenField(form, 'transaction', request.transaction);
+  appendHiddenField(form, 'operation', request.operation);
+  appendFormValue(form, 'data', request.data);
+
+  if (request.user) {
+    appendHiddenField(form, 'user', request.user);
+  }
+
+  document.body.appendChild(form);
+  form.submit();
+  form.remove();
+
+  return { transaction: request.transaction };
+}
+
+function appendHiddenField(form: HTMLFormElement, name: string, value: string): void {
+  const input = document.createElement('input');
+  input.type = 'hidden';
+  input.name = name;
+  input.value = value;
+  form.appendChild(input);
+}
+
+function appendFormValue(form: HTMLFormElement, name: string, value: unknown): void {
+  if (value === undefined) {
+    return;
+  }
+
+  if (value === null) {
+    appendHiddenField(form, name, '');
+    return;
+  }
+
+  if (Array.isArray(value)) {
+    value.forEach((item, index) => {
+      appendFormValue(form, `${name}[${index}]`, item);
+    });
+    return;
+  }
+
+  if (typeof value === 'object') {
+    Object.entries(value as Record<string, unknown>).forEach(([key, nestedValue]) => {
+      appendFormValue(form, `${name}[${key}]`, nestedValue);
+    });
+    return;
+  }
+
+  appendHiddenField(form, name, String(value));
+}

src/stores/entitiesStore.ts

@@ -7,7 +7,8 @@ import { defineStore } from 'pinia'
 import { entityService } from '../services'
 import { EntityObject, MessageObject } from '../models'
 import type {
-  EntityListStreamRequest,
+  EntityBlobSelector,
+  EntityDownloadRequest,
   EntityTransmitRequest,
   EntityTransmitResponse,
 } from '../types/entity'
@@ -18,7 +19,7 @@ import type {
   ListRange,
   ListSort,
 } from '../types/common'
-import type { MessageInterface } from '@/types/message'
+import type { MessageInterface, MessagePartInterface } from '@/types/message'
 
 export const useEntitiesStore = defineStore('mailEntitiesStore', () => {
   // State
@@ -184,15 +185,15 @@ export const useEntitiesStore = defineStore('mailEntitiesStore', () => {
       const response = await entityService.delta({ sources })
       
       // Process delta and update store
-      Object.entries(response).forEach(([provider, providerData]) => {
+      Object.entries(response).forEach(([, providerData]) => {
         // Skip if no changes for provider
         if (providerData === false) return
         
-        Object.entries(providerData).forEach(([service, serviceData]) => {
+        Object.entries(providerData).forEach(([, serviceData]) => {
           // Skip if no changes for service
           if (serviceData === false) return
           
-          Object.entries(serviceData).forEach(([collection, collectionData]) => {
+          Object.entries(serviceData).forEach(([, collectionData]) => {
             // Skip if no changes for collection
             if (collectionData === false) return
             
@@ -474,6 +475,39 @@ export const useEntitiesStore = defineStore('mailEntitiesStore', () => {
     }
   }
 
+  async function download(target: EntityIdentifier, part?: Partial<MessagePartInterface>) {
+    let targetPart: EntityBlobSelector | undefined = undefined
+    if (part && (part.blobId || part.partId || part.cid)) {
+      targetPart = {
+        blobId: part.blobId ?? undefined,
+        partId: part.partId ?? undefined,
+        cid: part.cid ?? undefined,
+      }
+    }
+
+    let filename: string
+    if (part && part.name && part.name.trim().length > 0) {
+      filename = part.name.trim()
+    } else if (part) {
+      filename = `attachment-${part.partId || part.blobId || part.cid || 'unknown'}`
+    } else {
+      filename = 'message.eml'
+    }
+
+    const request: EntityDownloadRequest = {
+      target,
+      part: targetPart,
+      filename,
+    }
+
+    try {
+      entityService.download(request)
+    } catch (error: any) {
+      console.error('[Mail Manager][Store] - Failed to submit attachment download:', error)
+      throw error
+    }
+  }
+
   // Return public API
   return {
     // State (readonly)
@@ -495,5 +529,6 @@ export const useEntitiesStore = defineStore('mailEntitiesStore', () => {
     delta,
     move,
     transmit,
+    download,
   }
 })

src/types/entity.ts

@@ -205,4 +205,32 @@ export interface EntityTransmitRequest {
 export interface EntityTransmitResponse {
   id: string;
   status: 'queued' | 'sent';
-}
+}
+
+/**
+ * Entity Blob Fetch
+ */
+export interface EntityBlobSelector {
+  blobId?: string;
+  partId?: string;
+  cid?: string;
+}
+
+export interface EntityDownloadRequest {
+  target: EntityIdentifier;
+  part?: EntityBlobSelector;
+  filename?: string | null;
+}
+
+export interface EntityBlobsRequest {
+  target: EntityIdentifier;
+  parts: EntityBlobSelector[];
+}
+
+export interface EntityBlobsResult {
+  source: EntityIdentifier;
+  part: EntityBlobSelector;
+  blob: Blob;
+}
+
+export interface EntityBlobsResponse extends Array<EntityBlobsResult> {}