Add Claude Sonnet 4.6 pricing (#21395)

* add Claude Sonnet 4.6 pricing across all platforms

* fix: correct Bedrock model names and add to BEDROCK_CONVERSE_MODELS

- Remove -v1 suffix from Bedrock Sonnet 4.6 entries per official docs
- Add anthropic.claude-sonnet-4-6 to BEDROCK_CONVERSE_MODELS

* fix: address Greptile and maintainer review feedback

- Update max_output_tokens from 8192 to 64000 (docs confirm 64K limit)
- Add search_context_cost_per_query to vertex_ai/claude-sonnet-4-6 for consistency
- Add vertex_ai/claude-sonnet-4-6@default variant per Vertex AI naming convention

litellm/constants.py

@@ -948,6 +948,9 @@ BEDROCK_CONVERSE_MODELS = [
     "openai.gpt-oss-120b-1:0",
     "anthropic.claude-haiku-4-5-20251001-v1:0",
     "anthropic.claude-sonnet-4-5-20250929-v1:0",
+    "anthropic.claude-opus-4-6-v1:0",
+    "anthropic.claude-opus-4-6-v1",
+    "anthropic.claude-sonnet-4-6",
     "anthropic.claude-opus-4-1-20250805-v1:0",
     "anthropic.claude-opus-4-20250514-v1:0",
     "anthropic.claude-sonnet-4-20250514-v1:0",