Complete iOS 27 Foundation Models provider adoption

[prasadpamidi]

Summary

• add typed Foundation Models failures and centralized error mapping
• build iOS 27 sessions with Dynamic Profiles while preserving the iOS 26 path
• bridge ordered Aria text/image content into Foundation Models prompts and transcript history
• support the same image path for text streaming and typed structured generation
• verify in-memory JPEG/PNG payloads, require declared vision support, and fail unsupported inputs explicitly
• bump Aria to 0.13.0 and document the multimodal contract

Why this PR includes the earlier branch

Niora already pins the reviewed Dynamic Profiles/multimodal commit bd5ff2c. Those prerequisite commits had not reached Aria main, so this PR reconciles the complete existing branch instead of introducing a second, narrower image bridge that would regress Niora's current API surface.

Verification

• DEVELOPER_DIR=/Applications/Xcode-beta.app/Contents/Developer bundle exec fastlane package_tests
• DEVELOPER_DIR=/Applications/Xcode-beta.app/Contents/Developer bundle exec fastlane quality

Latest package result: 84 AriaApple tests, 21 runtime/eval skips, 0 failures. Full package and quality lanes pass.