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>

package.json

@@ -108,10 +108,10 @@
     "@larksuiteoapi/node-sdk": "^1.58.0",
     "@line/bot-sdk": "^10.6.0",
     "@lydell/node-pty": "1.2.0-beta.3",
-    "@mariozechner/pi-agent-core": "0.51.6",
-    "@mariozechner/pi-ai": "0.51.6",
-    "@mariozechner/pi-coding-agent": "0.51.6",
-    "@mariozechner/pi-tui": "0.51.6",
+    "@mariozechner/pi-agent-core": "0.52.0",
+    "@mariozechner/pi-ai": "0.52.0",
+    "@mariozechner/pi-coding-agent": "0.52.0",
+    "@mariozechner/pi-tui": "0.52.0",
     "@mozilla/readability": "^0.6.0",
     "@sinclair/typebox": "0.34.48",
     "@slack/bolt": "^4.6.0",