0.8.0: pretty logger (Log) + crash capture

- Log: static entry + scoped Loggers (Log.tag), six levels, lazy messages,
  structured fields, ANSI ConsoleSink, DeveloperSink, MemorySink, NoopSink.
  Sinks compose via +; throwing sinks are isolated.
- Log.configure wires FlutterError/PlatformDispatcher/isolate errors through
  Log.e by default; log-then-rethrow deduped via Expando.
- UxKeyboard: migrate kDebugMode print() to Log.tag('KB').d lazily.
- Depend on package:clock for testable timestamps.

pubspec.lock

@@ -122,7 +122,7 @@ packages:
     source: hosted
     version: "2.0.4"
   clock:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: clock
       sha256: fddb70d9b5277016c77a80201021d40a2247104d9f4aa7bab7157b7e3f05b84b