fix: stable event hashing, HEAD fallback, caldav str/bytes compat

apply.py

@@ -5,8 +5,11 @@ from typing import Any
 logger = logging.getLogger(__name__)
 
 
-def _extract_uid(ical_data: bytes) -> str:
-    for line in ical_data.decode("utf-8", errors="replace").split("\r\n"):
+def _extract_uid(ical_data) -> str:
+    raw = ical_data
+    if isinstance(raw, bytes):
+        raw = raw.decode("utf-8", errors="replace")
+    for line in str(raw).split("\r\n"):
         if line.upper().startswith("UID:"):
             return line[4:].strip()
     return ""
@@ -15,7 +18,11 @@ def _extract_uid(ical_data: bytes) -> str:
 def _find_event_by_uid(calendar: Any, uid: str) -> Any | None:
     try:
         for event in calendar.events():
-            content = event.data.decode("utf-8", errors="replace")
+            raw = event.data
+            if isinstance(raw, bytes):
+                content = raw.decode("utf-8", errors="replace")
+            else:
+                content = str(raw)
             for line in content.split("\r\n"):
                 if line.upper().startswith("UID:"):
                     if line[4:].strip() == uid: