Merge remote-tracking branch 'refs/remotes/origin/worktree/web-multimodal-image-input' into worktree/pr555-simplify

# Conflicts:
#	.agents/notes/implemented/feature/2026-07-22-web-multimodal-image-input-and-durable-attachments.i18n.yaml
#	.agents/notes/implemented/feature/2026-07-22-web-multimodal-image-input-and-durable-attachments.md
#	.agents/notes/implemented/feature/2026-07-22-web-multimodal-image-input-and-durable-attachments.zh.md
#	apps/cli/README.i18n.yaml
#	apps/cli/README.md
#	apps/cli/README.zh.md
#	apps/cli/src/app-cli-entry.ts
#	packages/client/connection/src/client/fixture.ts
#	packages/client/ui-conversation/src/client/service.ts
#	packages/host/apiproxy/src/api-proxy.ts
#	packages/host/apiproxy/src/api/host.schema.ts
#	packages/host/apiproxy/src/api/host.ts
#	packages/host/apiproxy/tests/fetch-carrier.spec.ts

packages/client/ui-conversation/src/client/apply.ts

@@ -196,9 +196,9 @@ export function apply(ctx: Context): void {
       const shell = inputHub.shell(sessionId)
       return {
         keyboard: shell,
-        addImages: (files, current) => {
+        addImages: (files) => {
           try {
-            const images = conversation.createDraftImages(files, current)
+            const images = conversation.createDraftImages(files)
             shell.addImages(images.map(image => image.id))
             return null
           } catch (error: unknown) {

packages/client/ui-conversation/src/client/contract/slots.ts

@@ -273,7 +273,7 @@ export interface ComposerBarInjected {
   /** The InputBar-exclusive keyboard/DOM command face (decision 20 private plane). */
   keyboard: ComposerKeyboard
   /** Create browser previews and append their ids to the session input state. */
-  addImages: (files: readonly File[], current: readonly ComposerAttachment[]) => string | null
+  addImages: (files: readonly File[]) => string | null
   /** Release one browser preview and remove its id from the session input state. */
   removeImage: (id: string) => void
   /** Resolve ordered input-state ids to browser-owned draft attachments. */

packages/client/ui-conversation/src/client/service.ts

@@ -123,7 +123,6 @@ export class ConversationService extends Service implements IConversation {
     mode: 'queue' | 'steer',
     images: readonly File[],
   ): Promise<void> {
-    this.validateImages(images, [])
     const uploaded = await this.serializeImages(images)
     const content = [...uploaded, ...(text === '' ? [] : [{ type: 'text' as const, text }])]
     const result = await session.prompt(content, mode)
@@ -133,14 +132,10 @@ export class ConversationService extends Service implements IConversation {
   /**
    * Create runtime-only draft attachments and their object URLs.
    * @param files - browser-owned image files.
-   * @param current - images already present in the same composer.
    * @returns ordered attachment descriptors whose ids may enter the input state.
    */
-  createDraftImages(
-    files: readonly File[],
-    current: readonly ComposerAttachment[] = [],
-  ): readonly ComposerAttachment[] {
-    this.validateImages(files, current)
+  createDraftImages(files: readonly File[]): readonly ComposerAttachment[] {
+    for (const file of files) imageMediaType(file.type)
     return files.map((file) => {
       const attachment = browserDraftAttachment(file)
       this.draftAttachments.set(attachment.id, attachment)
@@ -276,36 +271,6 @@ export class ConversationService extends Service implements IConversation {
     return sessions
   }
 
-  /** Apply host-advertised fast-path checks before any object URL or base64 allocation. */
-  private validateImages(
-    files: readonly File[],
-    current: readonly ComposerAttachment[],
-  ): void {
-    if (files.length === 0 && current.length === 0) return
-    // Model capability is checked only by the host against the session's
-    // current target; the client owns deployment upload limits.
-    const description = this.requireSessions().hostDescription()
-    const limits = description?.imageLimits
-    const all = [...current.map(attachment => attachment.file), ...files]
-    if (limits !== undefined && all.length > limits.maxImagesPerMessage) {
-      throw new Error(`每条消息最多添加 ${limits.maxImagesPerMessage} 张图片`)
-    }
-    let totalBytes = 0
-    for (const file of all) {
-      const mediaType = imageMediaType(file.type)
-      if (limits !== undefined && !limits.mediaTypes.includes(mediaType)) {
-        throw new Error(`当前部署不支持 ${mediaType} 图片`)
-      }
-      if (limits !== undefined && file.size > limits.maxImageBytes) {
-        throw new Error(`图片 ${file.name || '未命名图片'} 超过单张大小限制`)
-      }
-      totalBytes += file.size
-    }
-    if (limits !== undefined && totalBytes > limits.maxMessageImageBytes) {
-      throw new Error('图片总大小超过单条消息限制')
-    }
-  }
-
   /** Convert browser files to the prompt wire's canonical base64 image parts. */
   private serializeImages(images: readonly File[]): Promise<Parameters<SessionFace['prompt']>[0]> {
     return Promise.all(images.map(async file => ({

packages/client/ui-conversation/src/client/skeleton/InputBar.tsx

@@ -234,7 +234,7 @@ export function InputBar({
       .map(item => item.getAsFile())
       .filter((file): file is File => file !== null)
     if (files.length > 0) {
-      setDropError(addImages(files, attachments))
+      setDropError(addImages(files))
     }
     const text = e.clipboardData.getData('text/plain')
     if (text === '') {
@@ -290,7 +290,7 @@ export function InputBar({
     if (locked || machineBusy) return
     const dropped = [...event.dataTransfer.files]
     if (dropped.length === 0) return
-    setDropError(addImages(dropped, attachments))
+    setDropError(addImages(dropped))
   }
 
   const closePreview = useCallback(() => { setPreview(null) }, [])