fix: code-review round 1 — 4 findings

- og: guard safe_abs_path's None (missing/gc'd poster) before _jpeg_size, else the public /watch OG
  render crashed with an uncaught AttributeError
- channels: hoist the priority step button to module scope so it no longer remounts on every
  hold-repeat tick (which dropped the pointer capture and could let a hold run away on pointer drift)
- watch: only route audio through Web Audio on iOS (where a backgrounded <video> is suspended);
  other platforms keep their reliable native audio, avoiding a foreground-silence risk if the
  AudioContext can't resume
- share: drop the unstable `create` mutation object from the auto-create effect deps (it changes
  every render); the links.data trigger + autoTried ref already fire it exactly once

The clipboard-on-focus finding is intended (the user explicitly asked for auto-paste on focus; the
read is best-effort and browsers reject it without a gesture, so no real prompt fires).

frontend/src/components/Channels.tsx

@@ -819,6 +819,46 @@ function SyncBadge({ ok, label, hint }: { ok: boolean; label: string; hint?: str
   );
 }
 
+// Module-level (NOT defined inside PriorityCell) so its identity is stable across PriorityCell
+// re-renders — otherwise every hold-repeat tick would remount the button and drop the pointer
+// capture set on pointerdown, letting a hold run away if the pointer drifts off the arrow.
+function PriorityStepButton({
+  delta,
+  Icon,
+  label,
+  onHoldStart,
+  onStop,
+  onTap,
+}: {
+  delta: number;
+  Icon: typeof ArrowUp;
+  label: string;
+  onHoldStart: (delta: number) => void;
+  onStop: () => void;
+  onTap: (delta: number) => void;
+}) {
+  return (
+    <button
+      onPointerDown={(e) => {
+        // Keep receiving pointer events even if the pointer drifts off the small button mid-hold.
+        try {
+          e.currentTarget.setPointerCapture(e.pointerId);
+        } catch {
+          /* invalid pointer id (e.g. synthetic events) — capture is a nicety, not required */
+        }
+        onHoldStart(delta);
+      }}
+      onPointerUp={onStop}
+      onPointerCancel={onStop}
+      onClick={() => onTap(delta)}
+      className="text-muted hover:text-accent leading-none"
+      aria-label={label}
+    >
+      <Icon className="w-3.5 h-3.5" />
+    </button>
+  );
+}
+
 function PriorityCell({
   c,
   onPriority,
@@ -858,7 +898,7 @@ function PriorityCell({
       tick();
     }, 350);
   };
-  const onClick = (delta: number) => {
+  const onTap = (delta: number) => {
     if (suppressClick.current) {
       suppressClick.current = false;
       return;
@@ -866,35 +906,6 @@ function PriorityCell({
     onPriority(delta);
   };
 
-  const StepBtn = ({
-    delta,
-    Icon,
-    label,
-  }: {
-    delta: number;
-    Icon: typeof ArrowUp;
-    label: string;
-  }) => (
-    <button
-      onPointerDown={(e) => {
-        // Keep receiving pointer events even if the pointer drifts off the small button mid-hold.
-        try {
-          e.currentTarget.setPointerCapture(e.pointerId);
-        } catch {
-          /* invalid pointer id (e.g. synthetic events) — capture is a nicety, not required */
-        }
-        start(delta);
-      }}
-      onPointerUp={stop}
-      onPointerCancel={stop}
-      onClick={() => onClick(delta)}
-      className="text-muted hover:text-accent leading-none"
-      aria-label={label}
-    >
-      <Icon className="w-3.5 h-3.5" />
-    </button>
-  );
-
   const commitEdit = () => {
     const parsed = parseInt(draft, 10);
     if (!Number.isNaN(parsed) && parsed !== c.priority) onSet(parsed);
@@ -941,8 +952,22 @@ function PriorityCell({
           )}
         </span>
         <span className="inline-flex flex-col">
-          <StepBtn delta={1} Icon={ArrowUp} label={t("channels.row.raisePriority")} />
-          <StepBtn delta={-1} Icon={ArrowDown} label={t("channels.row.lowerPriority")} />
+          <PriorityStepButton
+            delta={1}
+            Icon={ArrowUp}
+            label={t("channels.row.raisePriority")}
+            onHoldStart={start}
+            onStop={stop}
+            onTap={onTap}
+          />
+          <PriorityStepButton
+            delta={-1}
+            Icon={ArrowDown}
+            label={t("channels.row.lowerPriority")}
+            onHoldStart={start}
+            onStop={stop}
+            onTap={onTap}
+          />
         </span>
       </div>
     </Tooltip>