Adopt source-generated logging for runtime hot paths

[Copilot]

This updates the remaining high-traffic ILogger call sites to use LoggerMessage source generation instead of runtime template parsing. The change keeps the existing structured log shape while moving the formatting contract into compile-time generated helpers.

• Logging migration

  • Added per-namespace LogMessages partial classes with [LoggerMessage] definitions.
  • Replaced direct log.Log*("...", ...) calls in messaging, flows, assets, and hosting with generated helper methods.
  • Covered both parameterized logs and exception-bearing logs without changing the emitted message contracts.

• Touched runtime paths

  • Messaging consumers/subscriptions/transport cleaners across EF, Mongo, RabbitMQ, Kafka, Google Pub/Sub, Redis, and subscription fanout.
  • Flow execution and cron scheduling paths.
  • Asset store initialization and resize-service error paths.
  • Hosting timer error logging.

• Correctness fixes folded into the migration

  • Fixed the Kafka log-level gate so Kafka logs are emitted only when the level is enabled.
  • Corrected cron log message wording/parameter ordering in the touched path.
  • Removed an EF-specific log message that incorrectly referred to a MongoDB ID.

• Example

  internal static partial class LogMessages
  {
      [LoggerMessage(EventId = 1, Level = LogLevel.Error,
          Message = "Failed to consume message with type {type}.")]
      public static partial void FailedToConsumeMessage(
          ILogger logger,
          Exception exception,
          string type);
  }
  
  LogMessages.FailedToConsumeMessage(log, ex, source.TypeString);