feat(vision): add the model-facing recognition consumer

Registers the recognize_image tool and a bundled image-recognition skill,
and hooks agent/pre-step to deterministically inject the skill body when a
step input carries an image (content block or image path/URL), so the model
recognizes the image before continuing the task.

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

packages/vision/tool-image-recognition/tests/has-image-signal.spec.ts

@@ -0,0 +1,37 @@
+import { describe, expect, it } from 'vitest'
+import type { UserMessage } from '@deepseek-ai/dsh-session'
+import { hasImageSignal } from '../src/index.ts'
+
+function userMessage(blocks: UserMessage['content']): UserMessage {
+  return { id: 'u', role: 'user', source: { kind: 'user' }, content: blocks } as UserMessage
+}
+
+/** A content block carrying an image signal (the payload is irrelevant here). */
+function imageBlock(): UserMessage['content'][number] {
+  return { type: 'image', attachment: {} as never } as UserMessage['content'][number]
+}
+
+describe('hasImageSignal', () => {
+  it('detects an image content block when block detection is on', () => {
+    expect(hasImageSignal([userMessage([imageBlock()])], true, true)).toBe(true)
+  })
+
+  it('ignores image blocks when block detection is off', () => {
+    expect(hasImageSignal([userMessage([imageBlock()])], false, true)).toBe(false)
+  })
+
+  it('detects an image file path in text when path detection is on', () => {
+    const message = userMessage([{ type: 'text', text: 'transcribe /tmp/screenshot.png' }])
+    expect(hasImageSignal([message], true, true)).toBe(true)
+  })
+
+  it('detects an image URL in text', () => {
+    const message = userMessage([{ type: 'text', text: 'look at https://e.test/photo.JPG' }])
+    expect(hasImageSignal([message], true, true)).toBe(true)
+  })
+
+  it('ignores plain text with no image signal', () => {
+    const message = userMessage([{ type: 'text', text: 'summarize this document' }])
+    expect(hasImageSignal([message], true, true)).toBe(false)
+  })
+})