feat(ai): add adaptive thinking support for Claude Opus 4.6

- Add adaptive thinking mode (type: 'adaptive') for Opus 4.6+
- Add effort parameter ('low', 'medium', 'high', 'max') for adaptive thinking
- thinkingEnabled now auto-detects: adaptive for 4.6+, budget-based for older
- streamSimple/completeSimple map ThinkingLevel to effort levels for Opus 4.6
- Add tests for Opus 4.6 adaptive thinking and GPT-5.3 Codex
- Update @anthropic-ai/sdk to 0.73.0
- Update @aws-sdk/client-bedrock-runtime to 3.983.0
- Update @google/genai to 1.40.0
- Remove fast-xml-parser override (no longer needed)

package.json

@@ -48,7 +48,6 @@
 		"get-east-asian-width": "^1.4.0"
 	},
 	"overrides": {
-		"fast-xml-parser": "5.3.4",
 		"rimraf": "6.1.2",
 		"gaxios": {
 			"rimraf": "6.1.2"