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.

open-sse/providers/registry/commandcode.js

@@ -40,4 +40,8 @@ export default {
     { id: "Qwen/Qwen3.6-Plus", name: "Qwen 3.6 Plus" },
     { id: "stepfun/Step-3.5-Flash", name: "Step 3.5 Flash" },
   ],
+  features: {
+    usage: true,
+    usageApikey: true,
+  },
 };