Merging main into stable

[alexayers]

Summary (AI-generated)

Add branch safety checks, PR summary automation, and consolidate task status constants

Project Guidelines:

• Added mandatory branch safety check to prevent changes on main or stable branches

CI/CD:

• Created automated PR summary workflow using Claude API to generate concise diffs summaries on PR open/update

Backend (Dart):

• Extracted task status strings into TaskStatusValues constant class for single source of truth
• Updated AudioGenerationTaskRepositoryImpl and AudioService to use constants instead of hardcoded strings

Frontend (Flutter):

• Added TaskStatus status constants and refactored getters to use them
• Updated CreatePage and task status badge logic to reference constants instead of string literals
• Removed unused buildUri() helper from Configuration

API Client:

• Consolidated repetitive HTTP response validation into new _ok() helper method
• Replaced 50+ instances of inline status code checks with centralized error handling
• Inline buildUri() calls in login and download URL methods

Summary

Brief description of what this PR does.

Changes

• ...

Testing

How was this tested?

• dart analyze --fatal-infos passes (backend)
• flutter analyze --fatal-infos passes (UI)
• Tests pass
• Manually verified