Miscellaneous fixes (0.18 beta) (#23790)

* recreate review thumbnail directory before writing and log write failures

cleanup's remove_empty_directories() can rmdir an empty clips/review, after which thumbnail writes silently fail. Ensure the directory exists before both cv2.imwrite calls and check their return value

* add docs for add camera wizard

* Handle indefinite events when a segment needs to forcibly be ended for a ceamera

* update keyframe interval article link

---------

Co-authored-by: Nicolas Mowen <nickmowen213@gmail.com>

frigate/review/maintainer.py

@@ -115,9 +115,11 @@ class PendingReviewSegment:
         if self._frame is not None:
             self.thumb_time = datetime.datetime.now().timestamp()
             self.has_frame = True
-            cv2.imwrite(
+            Path(self.frame_path).parent.mkdir(parents=True, exist_ok=True)
+            if not cv2.imwrite(
                 self.frame_path, self._frame, [int(cv2.IMWRITE_WEBP_QUALITY), 60]
-            )
+            ):
+                logger.error("Failed to write review thumbnail to %s", self.frame_path)
 
     def save_full_frame(self, camera_config: CameraConfig, frame: np.ndarray) -> None:
         color_frame = cv2.cvtColor(frame, cv2.COLOR_YUV2BGR_I420)
@@ -128,9 +130,11 @@ class PendingReviewSegment:
 
         if self._frame is not None:
             self.has_frame = True
-            cv2.imwrite(
+            Path(self.frame_path).parent.mkdir(parents=True, exist_ok=True)
+            if not cv2.imwrite(
                 self.frame_path, self._frame, [int(cv2.IMWRITE_WEBP_QUALITY), 60]
-            )
+            ):
+                logger.error("Failed to write review thumbnail to %s", self.frame_path)
 
     def get_data(self, ended: bool) -> dict:
         end_time = None
@@ -374,6 +378,16 @@ class ReviewSegmentMaintainer(threading.Thread):
         """Forcibly end the pending segment for a camera."""
         segment = self.active_review_segments.get(camera)
         if segment:
+            if self.indefinite_events.get(camera):
+                self.indefinite_events[camera] = {}
+                now = datetime.datetime.now().timestamp()
+
+                if segment.last_alert_time == sys.maxsize:
+                    segment.last_alert_time = now
+
+                if segment.last_detection_time == sys.maxsize:
+                    segment.last_detection_time = now
+
             prev_data = segment.get_data(False)
             return self._publish_segment_end(segment, prev_data)
         return None