📝 clarify built sync target behavior

docs/api/build-application-logger.md

@@ -37,6 +37,7 @@ Detailed rules explaining key parameters and behaviors
 - The embedded config still goes through the normal runtime logger build path, including runtime sink selection, optional queue wrapping, and timestamp application.
 - Because the result is only the `ApplicationLogger` alias over `ConfiguredLogger`, this builder does not hide any queue, drain, flush, or file runtime helper methods.
 - The returned alias also keeps inherited `Logger` behavior such as `with_target(...)`, `child(...)`, and per-call `target=` overrides on `log(...)`.
+- That means `log(..., target=...)` can override the target for one write, while severity helpers such as `info(...)`, `warn(...)`, and `error(...)` continue to use the stored logger target unless a derived logger was created first with `with_target(...)` or `child(...)`.
 - Use this alias-oriented entrypoint when application boot code wants an app-specific name without changing the underlying configured runtime logger surface.
 
 ### How to Use
@@ -58,6 +59,18 @@ And any queue/file/runtime helpers selected by the config remain directly availa
 
 The returned value also keeps the ordinary logger target semantics because the facade does not wrap or narrow the underlying `ConfiguredLogger`.
 
+#### When Need A Per-call Target Override After App-oriented Build
+
+When typed app config should still build a logger that supports a one-write target override:
+```moonbit
+let logger = build_application_logger(config)
+logger.log(Level::Error, "boom", target="app.audit")
+```
+
+In this example, the emitted record uses `app.audit` for that write.
+
+And later `info(...)`, `warn(...)`, or `error(...)` calls still use the logger's stored target unless code derives another logger first with `with_target(...)` or `child(...)`.
+
 ### Error Case
 
 e.g.: