debug(player): log pause reason and flatten the debug tick

An unexplained pause/resume loop was invisible over adb: handlePause
logged nothing at all, so only the "playing" half of each cycle showed
up, and the 1s debug tick logged an object — which the Android WebView
console bridge renders as "[object Object]", discarding every field.

Log the element state on pause (readyState, networkState, seeking,
ended, plus the component's own isSeeking/isBuffering/handoff flags) and
emit the debug tick as a flat string. This is what identified DR-097:
the element was fully buffered and healthy at every pause, ruling out a
stall and pointing at a competing controller instead.

src/lib/components/player/VideoPlayer.svelte

@@ -686,15 +686,19 @@
           bufferedRanges.push(`[${buffered.start(i).toFixed(1)} - ${buffered.end(i).toFixed(1)}]`);
         }
 
-        console.log("[VideoPlayer Debug]", {
-          currentTime: videoElement.currentTime.toFixed(2),
-          displayTime: currentTime.toFixed(2),
-          buffered: bufferedRanges.join(", "),
-          readyState: videoElement.readyState,
-          paused: videoElement.paused,
-          seeking: videoElement.seeking,
-          playbackRate: videoElement.playbackRate,
-        });
+        // Flattened to a single string on purpose: the Android WebView console
+        // bridge stringifies objects as "[object Object]" in logcat, which made
+        // this whole payload useless when diagnosing over adb.
+        console.log(
+          `[VideoPlayer Debug] t=${videoElement.currentTime.toFixed(2)}` +
+            ` display=${currentTime.toFixed(2)}` +
+            ` readyState=${videoElement.readyState}` +
+            ` networkState=${videoElement.networkState}` +
+            ` paused=${videoElement.paused}` +
+            ` seeking=${videoElement.seeking}` +
+            ` rate=${videoElement.playbackRate}` +
+            ` buffered=${bufferedRanges.join(", ")}`
+        );
       }
     }, 1000);
   });
@@ -1101,6 +1105,21 @@
   }
 
   function handlePause() {
+    // The element pausing is normally user intent, but a stall, a source change,
+    // or a competing controller can also do it — and the pause itself carries no
+    // reason. Log the element state so an unexplained pause/resume loop can be
+    // attributed from an adb capture instead of guessed at.
+    const el = videoElement;
+    console.log(
+      `[VideoPlayer] pause event — t=${el ? el.currentTime.toFixed(2) : "?"}` +
+        ` readyState=${el?.readyState}` +
+        ` networkState=${el?.networkState}` +
+        ` seeking=${el?.seeking}` +
+        ` ended=${el?.ended}` +
+        ` isSeeking=${isSeeking}` +
+        ` isBuffering=${isBuffering}` +
+        ` handoff=${handoffState.active}`
+    );
     isPlaying = false;
     stopTimeUpdates(); // Stop RAF loop when paused
     html5Adapter.reportState("paused", reportMediaId ?? null);