📝 clarify async text builder docs

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

@@ -44,6 +44,7 @@ Detailed rules explaining key parameters and behaviors
 - Because the result is only the `ApplicationTextAsyncLogger` alias over `AsyncLogger[@bitlogger.FormattedConsoleSink]`, this builder returns the same underlying async logger value as `build_async_text_logger(...)` and does not hide any async helpers or introduce a wrapper layer.
 - The returned logger keeps the full async lifecycle and state helper surface directly, including helpers such as `run()`, `shutdown()`, `pending_count()`, `dropped_count()`, `state()`, `wait_idle()`, `has_failed()`, and `last_error()`.
 - It also keeps the same close, queue, and failure-state semantics as the underlying `AsyncLogger[@bitlogger.FormattedConsoleSink]`.
+- In the current direct text-builder coverage, this alias matches `build_async_text_logger(config)` through serialized state snapshots, formatter behavior, queue counters, lifecycle flags, and later failure fields after worker execution.
 - Its configured `flush_policy` is still visible on the returned alias, but this text-specific build path does not wire the explicit sink flush callback that `build_application_async_logger(...)` inherits through `build_async_logger(...)`.
 - That means `Batch` and `Shutdown` only drive the default no-op async flush callback here; they do not add an extra explicit sink flush step beyond ordinary `FormattedConsoleSink` writes.
 - Use `build_library_async_text_logger(...)` instead when the next boundary should keep the same concrete text sink type but intentionally narrow the directly exposed async helper surface.
@@ -84,6 +85,8 @@ e.g.:
 
 - If runtime draining is never started, records still follow the normal async queue lifecycle rules.
 
+- If callers rely on the formatter or state shape after text-builder construction, they should treat this as the same direct `build_async_text_logger(config)` result rather than a reduced alias with different helper behavior.
+
 ### Notes
 
 1. This is a narrower text-console async facade than `build_application_async_logger(...)`.