test(bedrock): upgrade cache TTL e2e model to Claude Sonnet 4.5

Switches the three new TTL integration tests from Claude Haiku 4.5 to
Claude Sonnet 4.5 via a _CACHE_TTL_MODEL_ID module constant. Sonnet 4.5 is
also officially documented as supporting 1h TTL per
https://docs.aws.amazon.com/bedrock/latest/userguide/prompt-caching.html
and the Sonnet tier typically has a longer support lifecycle than Haiku,
reducing the risk of the tests breaking due to model deprecation.

Extracting the ID into a module-level constant also makes future model
bumps a one-line change.

Author: kpx-dev

tests_integ/models/test_model_bedrock.py

@@ -9,6 +9,13 @@
 from strands.models import BedrockModel, CacheConfig
 from strands.types.content import ContentBlock
 
+# Model ID used for prompt-caching TTL integration tests. Per
+# https://docs.aws.amazon.com/bedrock/latest/userguide/prompt-caching.html
+# the models that officially support 1h TTL on CachePoint are
+# Claude Opus 4.5, Claude Haiku 4.5, and Claude Sonnet 4.5. Using Sonnet 4.5
+# here for longer expected support lifecycle than Haiku.
+_CACHE_TTL_MODEL_ID = "us.anthropic.claude-sonnet-4-5-20250929-v1:0"
+
 
 @pytest.fixture
 def system_prompt():
@@ -589,10 +596,12 @@ def test_prompt_caching_cache_tools_ttl():
     prefix because Bedrock's tool-prefix cache threshold varies by model and region.
     The critical behavior under test here is that the TTL field is accepted end-to-end.
 
-    Uses Claude Haiku 4.5 which supports TTL in CachePointBlock on Bedrock.
+    Uses Claude Sonnet 4.5 which supports TTL in CachePointBlock on Bedrock per
+    https://docs.aws.amazon.com/bedrock/latest/userguide/prompt-caching.html
+    (Claude Opus 4.5, Claude Haiku 4.5, and Claude Sonnet 4.5 all support 1h TTL).
     """
     model = BedrockModel(
-        model_id="us.anthropic.claude-haiku-4-5-20251001-v1:0",
+        model_id=_CACHE_TTL_MODEL_ID,
         streaming=False,
         cache_tools="default",
         cache_tools_ttl="5m",
@@ -624,10 +633,11 @@ def test_prompt_caching_cache_config_auto_with_ttl():
     Verifies that the cache point appended to the last user message by _inject_cache_point
     carries the configured TTL, and that Bedrock accepts the request.
 
-    Uses Claude Haiku 4.5 which supports TTL in CachePointBlock on Bedrock.
+    Uses Claude Sonnet 4.5 which supports TTL in CachePointBlock on Bedrock per
+    https://docs.aws.amazon.com/bedrock/latest/userguide/prompt-caching.html
     """
     model = BedrockModel(
-        model_id="us.anthropic.claude-haiku-4-5-20251001-v1:0",
+        model_id=_CACHE_TTL_MODEL_ID,
         streaming=False,
         cache_config=CacheConfig(strategy="auto", ttl="5m"),
     )
@@ -662,10 +672,11 @@ def test_prompt_caching_aligned_1h_ttl_across_checkpoints():
     This test sets 1h TTL on all three checkpoints simultaneously and verifies the
     call succeeds.
 
-    Uses Claude Haiku 4.5 which supports 1h TTL.
+    Uses Claude Sonnet 4.5 which supports 1h TTL per
+    https://docs.aws.amazon.com/bedrock/latest/userguide/prompt-caching.html
     """
     model = BedrockModel(
-        model_id="us.anthropic.claude-haiku-4-5-20251001-v1:0",
+        model_id=_CACHE_TTL_MODEL_ID,
         streaming=False,
         cache_tools="default",
         cache_tools_ttl="1h",