✨ Add explicit configured file flush and close helpers

bitlogger/BitLogger_test.mbt

@@ -231,3 +231,43 @@ test "configured logger can reopen built file sink" {
     inspect(logger.file_open_failures(), content="2")
   }
 }
+
+test "configured logger exposes file flush and close helpers" {
+  let logger = build_logger(
+    LoggerConfig::new(
+      sink=SinkConfig::new(kind=SinkKind::File, path="config-control.log"),
+    ),
+  )
+  if logger.file_available() {
+    logger.info("before flush")
+    inspect(logger.file_flush(), content="true")
+    inspect(logger.file_close(), content="true")
+    inspect(logger.file_available(), content="false")
+    inspect(logger.file_flush(), content="false")
+  } else {
+    inspect(logger.file_flush(), content="false")
+    inspect(logger.file_close(), content="false")
+  }
+}
+
+test "configured queued file logger flushes queue through file helper" {
+  let logger = build_logger(
+    LoggerConfig::new(
+      sink=SinkConfig::new(kind=SinkKind::File, path="config-queued-file.log"),
+      queue=Some(QueueConfig::new(4, overflow=QueueOverflowPolicy::DropNewest)),
+    ),
+  )
+  logger.info("one")
+  logger.info("two")
+  if logger.file_available() {
+    inspect(logger.pending_count(), content="2")
+    inspect(logger.file_flush(), content="true")
+    inspect(logger.pending_count(), content="0")
+    inspect(logger.file_close(), content="true")
+  } else {
+    inspect(logger.pending_count(), content="2")
+    inspect(logger.file_flush(), content="false")
+    inspect(logger.pending_count(), content="0")
+    inspect(logger.file_close(), content="false")
+  }
+}

bitlogger/README.mbt.md

@@ -222,5 +222,5 @@ test {
 - JSON config uses `sink.rotation.max_bytes` and `sink.rotation.max_backups` / JSON 配置使用 `sink.rotation.max_bytes` 与 `sink.rotation.max_backups`
 - `FileSink::reopen()` can explicitly reopen the current file handle / `FileSink::reopen()` 可显式重开当前文件句柄
 - `open_failures()`、`write_failures()`、`flush_failures()`、`rotation_failures()` expose basic sink health counters / `open_failures()`、`write_failures()`、`flush_failures()`、`rotation_failures()` 可用于观察基础 sink 健康状态
-- `ConfiguredLogger` also forwards file reopen and failure-counter helpers for config-built file sinks / `ConfiguredLogger` 也会为配置生成的 file sink 转发 reopen 与失败计数访问器
+- `ConfiguredLogger` also forwards file reopen, flush, close, and failure-counter helpers for config-built file sinks / `ConfiguredLogger` 也会为配置生成的 file sink 转发 reopen、flush、close 与失败计数访问器
 - current scope is observability-first, not a full self-healing sink runtime / 当前定位仍以可观测性优先，不是完整自愈型 sink runtime

bitlogger/config.mbt

@@ -231,6 +231,28 @@ pub fn RuntimeSink::file_reopen(self : RuntimeSink, append~ : Bool? = None) -> B
   }
 }
 
+pub fn RuntimeSink::file_flush(self : RuntimeSink) -> Bool {
+  match self {
+    File(sink) => sink.flush()
+    QueuedFile(sink) => {
+      ignore(sink.flush())
+      sink.sink.flush()
+    }
+    _ => false
+  }
+}
+
+pub fn RuntimeSink::file_close(self : RuntimeSink) -> Bool {
+  match self {
+    File(sink) => sink.close()
+    QueuedFile(sink) => {
+      ignore(sink.flush())
+      sink.sink.close()
+    }
+    _ => false
+  }
+}
+
 pub fn RuntimeSink::file_open_failures(self : RuntimeSink) -> Int {
   match self {
     File(sink) => sink.open_failures()
@@ -293,6 +315,14 @@ pub fn ConfiguredLogger::file_reopen(self : ConfiguredLogger, append~ : Bool? =
   self.sink.file_reopen(append=append)
 }
 
+pub fn ConfiguredLogger::file_flush(self : ConfiguredLogger) -> Bool {
+  self.sink.file_flush()
+}
+
+pub fn ConfiguredLogger::file_close(self : ConfiguredLogger) -> Bool {
+  self.sink.file_close()
+}
+
 pub fn ConfiguredLogger::file_open_failures(self : ConfiguredLogger) -> Int {
   self.sink.file_open_failures()
 }