📝 Update More API Document

docs/api/build-application-async-logger.md

@@ -0,0 +1,71 @@
+---
+name: build-application-async-logger
+group: api
+category: facade
+update-time: 20260520
+description: Build the application-facing async logger facade from an AsyncLoggerBuildConfig.
+key-word:
+    - application
+    - async
+    - facade
+    - public
+---
+
+## Build-application-async-logger
+
+Build an `ApplicationAsyncLogger` from `AsyncLoggerBuildConfig`. This is the application-facing async facade over `build_async_logger(...)`.
+
+### Interface
+
+```moonbit
+pub fn build_application_async_logger(
+  config : AsyncLoggerBuildConfig,
+) -> ApplicationAsyncLogger {
+```
+
+#### input
+
+- `config : AsyncLoggerBuildConfig` - Combined sync logger config and async queue/runtime config.
+
+#### output
+
+- `ApplicationAsyncLogger` - Application-facing async runtime logger.
+
+### Explanation
+
+Detailed rules explaining key parameters and behaviors
+
+- This API delegates to `build_async_logger(...)`.
+- The returned logger keeps the standard async lifecycle and state helper surface.
+- Use this facade when application code wants a dedicated async app-level entry point.
+
+### How to Use
+
+Here are some specific examples provided.
+
+#### When Need Config-driven App Async Boot
+
+When both sync sink shape and async queue policy are assembled as typed config:
+```moonbit
+let logger = build_application_async_logger(
+  AsyncLoggerBuildConfig::new(
+    logger=LoggerConfig::new(target="app.async"),
+    async_config=AsyncLoggerConfig::new(max_pending=8),
+  ),
+)
+```
+
+In this example, the app-facing async facade is built directly from typed config.
+
+### Error Case
+
+e.g.:
+- If file output is selected on a backend without native file support, backend behavior still applies when the worker drains records.
+
+- If the logger is never `run()`, enqueue behavior and lifecycle state still follow the normal async logger rules.
+
+### Notes
+
+1. This is a facade over the existing async runtime logger builder.
+
+2. Use `parse_and_build_application_async_logger(...)` when starting from JSON text.