fix(commandcode): preserve images and reasoning_effort on /alpha/generate

Command Code dropped vision and ignored client effort through the router:
image blocks became "[image omitted]", HTTP image URLs were never inlined,
and reasoning_effort landed on the envelope wrapper instead of params (so the
DeepSeek family mapping remapped low -> high). The catalog also treated
deepseek/deepseek-v4.1-flash as text-only, so the vision adapter stole those
requests to another provider.

- Map OpenAI image_url / Claude image blocks (base64 or data-URI) to the
  native {type:"image", image:"data:...;base64,...", mimeType} generate block.
- Add FORMATS.COMMANDCODE to TARGETS_NEED_BASE64 so remote http(s) images are
  inlined by the existing SSRF-safe fetcher before translation.
- Write reasoning_effort inside params for targetFormat commandcode and pass
  low|medium|high|xhigh|max through unmapped; allow it in thinkingLevels.
- Provider-scoped capabilities for commandcode/cmc: vision except the CLI
  text-only denylist, thinkingFormat commandcode, so family patterns
  (deepseek-v4 -> thinkingFormat deepseek, vision false) no longer win.
- Quota Tracker: whoami + billing credits/subscriptions (credits vs plan cap,
  5h and weekly windows), labels from AI_PROVIDERS[].name.

tests/unit/prefetch-images.test.js

@@ -55,4 +55,21 @@ describe("prefetchRemoteImages", () => {
     expect(n).toBe(1);
     expect(body.messages[0].content[0].source.type).toBe("base64");
   });
+
+  it("openai source -> commandcode target: converts remote URL to base64", async () => {
+    const body = { messages: [{ role: "user", content: [{ type: "image_url", image_url: { url: "https://x/a.png" } }] }] };
+    const n = await prefetchRemoteImages(body, FORMATS.OPENAI, FORMATS.COMMANDCODE);
+    expect(n).toBe(1);
+    expect(body.messages[0].content[0].image_url.url.startsWith("data:image/png;base64,")).toBe(true);
+    expect(fetchImageAsBase64).toHaveBeenCalled();
+  });
+
+  it("claude source -> commandcode target: source.url -> base64", async () => {
+    const body = { messages: [{ role: "user", content: [
+      { type: "image", source: { type: "url", url: "https://x/a.png" } },
+    ] }] };
+    const n = await prefetchRemoteImages(body, FORMATS.CLAUDE, FORMATS.COMMANDCODE);
+    expect(n).toBe(1);
+    expect(body.messages[0].content[0].source.type).toBe("base64");
+  });
 });