Speed up dev-lint SwiftLint discovery

[baron]

Summary

• Switch full-repo Scripts/swift_style.sh lint to config-discovered SwiftLint with --quiet --force-exclude, avoiding SCRIPT_INPUT_FILE_* overhead.
• Align .swiftlint.yml include/exclude scope with the wrapper's first-party Swift style scope, including generated/vendor/build/transient paths and large workflow prompt files.
• Add a regression test to guard against reintroducing script-input mode and to keep SwiftLint config includes aligned with STYLE_PATHS.

Closes #426.

Validation

• python3 -m unittest Scripts.test_release_tooling.ReleaseToolingTests.test_swift_style_lint_uses_config_discovery_without_script_input_overhead
• bash -n Scripts/swift_style.sh
• /usr/bin/time -p make dev-lint
  • Post-rebase conductor ticket: a695917e-ff5f-43a8-b9b6-57b68d284c14
  • Passed; SwiftLint command shown as swiftlint lint --strict --config .../.swiftlint.yml --quiet --force-exclude
• .agents/skills/rpce-contribution-check/scripts/preflight.sh commit
• .agents/skills/rpce-contribution-check/scripts/preflight.sh push

Review

• Claude Fable 5 read-only review found no must-fix issues and concluded lint/formatting integrity is preserved.
• Folded in its suggested test hardening for .swiftlint.yml included: parity with STYLE_PATHS.