Release 0.10.1: cross-platform support + loopback http exemption

[angeltabar]

Summary

Release 0.10.1 (patch).

Added

• Cross-platform capability gating (PlatformSupport). Attachment and avatar UI now degrade gracefully on platforms whose plugins don't cover every target: camera capture and image crop are offered on mobile (crop mobile-only), while downloaded files open natively on mobile and fall back to the OS default handler via url_launcher on desktop. Derived from kIsWeb + defaultTargetPlatform (never dart:io), so it resolves on web too — hiding controls a platform can't honour instead of surfacing ones that silently fail.
• Example app builds for desktop and web (Linux/macOS/Windows/web). The generated runners are gitignored to keep the published package lean; regenerate with flutter create ..

Changed

• ChatConfig URL validation exempts loopback hosts (localhost, 127.0.0.0/8, ::1) from the release-mode HTTPS requirement — loopback never leaves the device and every platform treats it as a secure context — while every other host still requires https:// (pentest M-10). The 127. match is anchored to an IPv4 literal so a DNS host like 127.evil.com isn't mistaken for loopback.

Housekeeping

• Bump pubspec.yaml + the runtime nomaChatSdkVersion constant to 0.10.1 (kept in lockstep by version_sync_test).
• Remove stray flutter run logs; gitignore *.log and the example desktop/web runners.

Verification

• dart format --set-exit-if-changed ✓
• flutter analyze --fatal-infos --fatal-warnings ✓ (0 issues)
• flutter test ✓ (2729 passed)
• dart pub publish --dry-run validates (warnings only about the pre-commit dirty tree, now resolved).