Use sonnet 4.6 as default in anthropic

[rumpl]

Same price, better model

[docker-agent]

Assessment: 🟢 APPROVE

The production-code change is correct and well-scoped — bumping DefaultModels["anthropic"] from "claude-sonnet-4-5" to "claude-sonnet-4-6".

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ℹ️ Note: test file needs updating

pkg/config/auto_test.go still hardcodes "claude-sonnet-4-5" in several places that test the default model value:

Location	Test
line 171	TestAutoModelConfig – "anthropic provider" subcase
line 213	TestAutoModelConfig – "gateway defaults to anthropic" subcase
line 291	TestDefaultModels – direct assert.Equal(t, "claude-sonnet-4-5", DefaultModels["anthropic"])
line 442	TestAutoModelConfig_UserDefaultModel – "empty model falls back to auto detection" subcase

These assertions depend on DefaultModels["anthropic"] returning the old value and will fail with task test as-is. (Lines 469/477 in the same file set "claude-sonnet-4-5" as an explicit user-supplied model and are unaffected — they test that user-provided models are preserved, not the default.)

[dgageot]

@rumpl It's in the tests too

[rumpl]

@rumpl It's in the tests too

fixed

[rumpl]

OMG HOW MANY TIMES ARE WE CHECKING FOR THIS