(#692) Fix duration mismatch between audio and metadata

When an audio file is played and the duration from the passed properties
does not match the duration of the actual audio file, e.g. the duration
was rounded, the progress bar drifts outside of the total width of the
VWaveform dimensions.

On smaller width screens or larger tracks it is less noticeable but when
the audio track is small and the screen width is large that percentage
adds up to 10s or more of pixels which is where the bug crops up.

This commit fixes this issue by by using the audio context's duration
parameter and falling back to less specific sources for duration.

src/components/VAudioTrack/VAudioTrack.vue

@@ -285,7 +285,9 @@ export default defineComponent({
 
     /* Timekeeping */
 
-    const duration = computed(() => (props.audio?.duration ?? 0) / 1e3) // seconds
+    const duration = computed(
+      () => (localAudio?.duration ?? props.audio?.duration ?? 0) / 1e3 // seconds
+    )
 
     const message = computed(() => store.state.active.message)
 

src/components/VAudioTrack/VGlobalAudioTrack.vue

@@ -189,7 +189,10 @@ export default defineComponent({
 
     /* Timekeeping */
 
-    const duration = computed(() => (props.audio?.duration ?? 0) / 1e3) // seconds
+    const duration = computed(
+      () =>
+        (activeAudio.obj.value?.duration ?? props.audio?.duration ?? 0) / 1e3
+    ) // seconds
 
     const message = computed(() => store.state.active.message)