feat: add model-aware DSH image input

DeepSeek Harness previously treated every selected model as text-only. It now carries the model profile's image capability through Main, the Utility Host, ACP, and Pi-AI, rejects unsupported images before model invocation, and validates supported JPEG/PNG data in a bounded process-local attachment store.

The Composer keeps universal controls on its first row, places OpenCode and Continue controls on a dedicated responsive row, and anchors context compaction without shifting the footer. Runtime supervision ownership for future Subagents and Jobs is documented for the right sidebar.

Release note: DeepSeek Harness 现可按所选模型连接的能力安全接收 JPEG/PNG 图片；Composer 同时将 Runtime 专属选择器移到独立一行，并固定上下文压缩入口。

tests/build-release.test.ts

@@ -330,7 +330,9 @@ describe('release build arguments', () => {
         'node_modules/node-pty/prebuilds/**/*',
         'node_modules/node-pty/build/Release/**/*',
         'node_modules/koffi/**/*',
-        'node_modules/@koromix/koffi-*/**/*'
+        'node_modules/@koromix/koffi-*/**/*',
+        'node_modules/@napi-rs/canvas{,/**/*}',
+        'node_modules/@napi-rs/canvas-*/**/*'
       ])
     )
     expect(packageJson.build.asarUnpack).not.toContain(