feat: temporary file handling and introduce TempDirCleaner (#5026)

* feat: temporary file handling and introduce TempDirCleaner

- Updated various modules to use `get_astrbot_temp_path()` instead of `get_astrbot_data_path()` for temporary file storage.
- Renamed temporary files for better identification and organization.
- Introduced `TempDirCleaner` to manage the size of the temporary directory, ensuring it does not exceed a specified limit by deleting the oldest files.
- Added configuration option for maximum temporary directory size in the dashboard.
- Implemented tests for `TempDirCleaner` to verify cleanup functionality and size management.

* ruff

tests/test_temp_dir_cleaner.py

@@ -0,0 +1,52 @@
+import os
+import time
+from pathlib import Path
+
+from astrbot.core.utils.temp_dir_cleaner import TempDirCleaner, parse_size_to_bytes
+
+
+def test_parse_size_to_bytes():
+    assert parse_size_to_bytes("1024") == 1024 * 1024**2
+    assert parse_size_to_bytes(2048) == 2048 * 1024**2
+    assert parse_size_to_bytes("0.5") == int(0.5 * 1024**2)
+    assert parse_size_to_bytes(0) == 0
+    assert parse_size_to_bytes("invalid") == 0
+
+
+def _write_file(path: Path, size: int, mtime: float) -> None:
+    path.write_bytes(b"x" * size)
+    os.utime(path, (mtime, mtime))
+
+
+def test_cleanup_once_releases_30_percent_and_prefers_old_files(tmp_path):
+    temp_dir = tmp_path / "temp"
+    temp_dir.mkdir(parents=True, exist_ok=True)
+
+    base_time = time.time() - 1000
+    file_old = temp_dir / "old.bin"
+    file_mid = temp_dir / "mid.bin"
+    file_new = temp_dir / "new.bin"
+    _write_file(file_old, 400, base_time)
+    _write_file(file_mid, 300, base_time + 10)
+    _write_file(file_new, 300, base_time + 20)
+
+    cleaner = TempDirCleaner(max_size_getter=lambda: "0.0008", temp_dir=temp_dir)
+    cleaner.cleanup_once()
+
+    remaining_size = sum(f.stat().st_size for f in temp_dir.rglob("*") if f.is_file())
+    assert remaining_size <= 600
+    assert not file_old.exists()
+    assert file_mid.exists()
+    assert file_new.exists()
+
+
+def test_cleanup_once_noop_when_below_limit(tmp_path):
+    temp_dir = tmp_path / "temp"
+    temp_dir.mkdir(parents=True, exist_ok=True)
+    file_path = temp_dir / "a.bin"
+    _write_file(file_path, 100, time.time())
+
+    cleaner = TempDirCleaner(max_size_getter=lambda: "1", temp_dir=temp_dir)
+    cleaner.cleanup_once()
+
+    assert file_path.exists()