📝 Add configured logger file control API docs

docs/api/configured-logger-file-reopen-with-current-policy.md

@@ -0,0 +1,74 @@
+---
+name: configured-logger-file-reopen-with-current-policy
+group: api
+category: runtime
+update-time: 20260512
+description: Reopen the file sink behind a configured runtime logger using its currently stored runtime policy.
+key-word:
+    - logger
+    - runtime
+    - file
+    - public
+---
+
+## Configured-logger-file-reopen-with-current-policy
+
+Reopen the file sink behind a `ConfiguredLogger` using the currently stored runtime policy. This helper is useful when callers want recovery behavior without supplying a one-off append override.
+
+### Interface
+
+```moonbit
+pub fn ConfiguredLogger::file_reopen_with_current_policy(self : ConfiguredLogger) -> Bool {}
+```
+
+#### input
+
+- `self : ConfiguredLogger` - Config-driven runtime logger whose file sink should be reopened with current policy.
+
+#### output
+
+- `Bool` - Whether reopen succeeded.
+
+### Explanation
+
+Detailed rules explaining key parameters and behaviors
+
+- Plain file sinks reuse their current stored reopen policy.
+- Queued file sinks forward reopen behavior to the wrapped file sink.
+- This helper differs from `file_reopen(...)` because it does not accept a per-call append override.
+- Non-file sinks return `false`.
+
+### How to Use
+
+Here are some specific examples provided.
+
+#### When Need Policy-preserving Recovery
+
+When a file sink should be reopened without changing runtime append behavior:
+```moonbit
+ignore(logger.file_reopen_with_current_policy())
+```
+
+In this example, recovery reuses the runtime policy already stored on the sink.
+
+#### When Separate Recovery From Policy Mutation
+
+When append mode should be controlled elsewhere:
+```moonbit
+let ok = logger.file_reopen_with_current_policy()
+```
+
+In this example, reopen is explicit while policy mutation stays separate.
+
+### Error Case
+
+e.g.:
+- If the configured sink is not file-backed, the method returns `false`.
+
+- If callers want to change append behavior during reopen, `file_reopen(...)` or `file_reopen_append()` / `file_reopen_truncate()` are better APIs.
+
+### Notes
+
+1. Use this helper when recovery should respect the currently stored runtime policy.
+
+2. It is clearer than passing no override through a more general reopen API.