chore(deps): clean up package dependency scopes

[leoafarias]

Summary

• Move path in ack_generator to dev_dependencies because it is only used by tests/tooling.
• Move firebase_ai in ack_firebase_ai to dev_dependencies because package library code does not import it directly.
• Add ack_annotations to the example dependencies because example/lib imports it directly.

Validation

• dart analyze . --fatal-warnings --fatal-infos for all workspace packages
• dependency_validator --verbose -C <package> for each package
• dart test in packages/ack, packages/ack_generator, packages/ack_json_schema_builder, and example
• flutter test in packages/ack_firebase_ai
• cd tools && npm install --silent && npx depcheck --json

Notes

• Melos orchestration is blocked in this workspace because pubspec.yaml points to .fvm/flutter_sdk, which is not present locally, so validation used direct package-level commands.

[docs-page]

To view this pull requests documentation preview, visit the following URL:

docs.page/btwld/ack~112

Documentation is deployed and generated using docs.page.