feat: add Claude Opus 4.6 to built-in model catalog (#9853)

* feat: add Claude Opus 4.6 to built-in model catalog

- Update default model from claude-opus-4-5 to claude-opus-4-6
- Add opus-4.6 model ID normalization
- Add claude-opus-4-6 to live model filter prefixes
- Update image tool to prefer claude-opus-4-6 for vision
- Add CLI backend alias for opus-4.6
- Update onboard auth default selections to include opus-4.6
- Update model picker placeholder

Closes #9811

* test: update tests for claude-opus-4-6 default

- Fix model-alias-defaults test to use claude-opus-4-6
- Fix image-tool test to expect claude-opus-4-6 in fallbacks

* feat: support claude-opus-4-6

* docs: update changelog for opus 4.6 (#9853) (thanks @TinyTb)

* chore: bump pi to 0.52.0

---------

Co-authored-by: Slurpy <slurpy@openclaw.ai>
Co-authored-by: Peter Steinberger <steipete@gmail.com>

src/agents/tools/image-tool.test.ts

@@ -53,7 +53,7 @@ describe("image tool implicit imageModel config", () => {
     };
     expect(resolveImageModelConfigForTool({ cfg, agentDir })).toEqual({
       primary: "minimax/MiniMax-VL-01",
-      fallbacks: ["openai/gpt-5-mini", "anthropic/claude-opus-4-5"],
+      fallbacks: ["openai/gpt-5-mini", "anthropic/claude-opus-4-6"],
     });
     expect(createImageTool({ config: cfg, agentDir })).not.toBeNull();
   });