✨ Add file policy reset helpers

docs/README-en.md

@@ -231,10 +231,12 @@ match logger.file_runtime_state() {
 - `file_sink(...)` also exposes `rotation_enabled()` and `rotation_config()` for reading whether rotation is active and which parameters are currently in effect.
 - `file_sink(...)` also exposes `state()` for reading a single snapshot that includes path, availability, append policy, auto-flush flag, rotation config, and all current failure counters.
 - `file_sink(...)` also exposes `reset_failure_counters()` so open/write/flush/rotation failure counters can be cleared after diagnostics or recovery handling.
+- `file_sink(...)` also exposes `reset_policy()` so append, auto-flush, and rotation settings can be restored to the sink's original defaults.
 - `file_sink(...)` also supports `set_auto_flush(...)`, `set_rotation(...)`, and `clear_rotation()` for runtime policy updates.
 - `ConfiguredLogger` built through `build_logger(...)` also exposes `file_reopen()`, `file_reopen_with_current_policy()`, `file_reopen_append()`, `file_reopen_truncate()`, `file_flush()`, `file_close()`, `file_append_mode()`, `file_path()`, `file_auto_flush()`, `file_rotation_enabled()`, `file_rotation_config()`, `file_state()`, plus `file_set_append_mode(...)`, `file_set_auto_flush(...)`, `file_set_rotation(...)`, `file_clear_rotation()`, and the corresponding file failure counters, so config-driven file logging keeps a usable control surface.
 - `ConfiguredLogger` also exposes `file_runtime_state()` so queued file loggers can report both the underlying file snapshot and the outer queue backlog/drop state in one read.
 - `ConfiguredLogger` also exposes `file_reset_failure_counters()` for clearing file failure counters through the config-built control surface.
+- `ConfiguredLogger` also exposes `file_reset_policy()` for restoring runtime file policy back to the initial config values.
 - `file_sink_state_to_json(...)`, `stringify_file_sink_state(...)`, `runtime_file_state_to_json(...)`, and `stringify_runtime_file_state(...)` can export file and queued-file snapshots directly as JSON for diagnostics or reporting.
 - `sink.text_formatter.template` currently supports fixed tokens: `{timestamp}`, `{timestamp_ms}`, `{level}`, `{target}`, `{message}`, and `{fields}`.
 - Config-driven sink assembly currently supports `console`, `json_console`, `text_console`, and `file`.

docs/changes/0.3.0.md

@@ -43,6 +43,7 @@ version 0.3.0
 - feat: add `RuntimeFileState` and `file_runtime_state()` so config-built queued file sinks can expose outer queue backlog/drop state together with inner file state
 - feat: add JSON export helpers for `FileSinkState` and `RuntimeFileState` so runtime file snapshots can be dumped directly for diagnostics
 - feat: add `reset_failure_counters()` / `file_reset_failure_counters()` so file failure counters can be cleared after diagnostics or recovery handling
+- feat: add `reset_policy()` / `file_reset_policy()` so runtime append, auto-flush, and rotation settings can be restored to their initial defaults
 - feat: add `SplitSink`, `split_sink(...)`, and `split_by_level(...)` for routing records into different sinks by predicate or level
 - feat: add `Logger::bind(...)` as an ergonomic context-binding alias and `fields(...)` helper for tuple-based field construction