chore: bump bedrock models to sonnet-4.5

[joanagmaia]

Note

Medium Risk
Changes the underlying LLM model and Bedrock region for multiple production workflows, which can alter output quality/behavior and has potential availability/latency implications, but is configuration-scoped with minimal logic changes.

Overview
Upgrades Amazon Bedrock model usage to Claude Sonnet 4.5 (us.anthropic.claude-sonnet-4-5-20250929-v1:0) across the codebase, including crowdgit’s invoke_bedrock and the Temporal merge-suggestion workflows.

Introduces LlmModelType.CLAUDE_SONNET_4_5 and wires it into shared LLM_SETTINGS, plus adds region/pricing mappings; merge workflows also switch from hardcoded model IDs to the enum and move execution to us-west-2.

^{Written by Cursor Bugbot for commit 15af6b2. This will update automatically on new commits. Configure here.}

[github-actions]

⚠️ Jira Issue Key Missing

Your PR title doesn't contain a Jira issue key. Consider adding it for better traceability.

Example:

• feat: add user authentication (CM-123)
• feat: add user authentication (IN-123)

Projects:

• CM: Community Data Platform
• IN: Insights

Please add a Jira issue key to your PR title.

[github-actions]

⚠️ Jira Issue Key Missing

Your PR title doesn't contain a Jira issue key. Consider adding it for better traceability.

Example:

• feat: add user authentication (CM-123)
• feat: add user authentication (IN-123)

Projects:

• CM: Community Data Platform
• IN: Insights

Please add a Jira issue key to your PR title.

[github-actions]

⚠️ Jira Issue Key Missing

Your PR title doesn't contain a Jira issue key. Consider adding it for better traceability.

Example:

• feat: add user authentication (CM-123)
• feat: add user authentication (IN-123)

Projects:

• CM: Community Data Platform
• IN: Insights

Please add a Jira issue key to your PR title.

[skwowet]

Just left a comment about the region prefix, but LGTM overall.

[github-actions]

⚠️ Jira Issue Key Missing

Your PR title doesn't contain a Jira issue key. Consider adding it for better traceability.

Example:

• feat: add user authentication (CM-123)
• feat: add user authentication (IN-123)

Projects:

• CM: Community Data Platform
• IN: Insights

Please add a Jira issue key to your PR title.