Move slideshow interval control to album page; fix mobile viewport clipping

- Interval input (default 5 s) now lives beside Shuffle/Full screen on
  the album page; passed as ?interval= param to the slideshow and seeded
  into the hidden ss-interval input on load.
- Added "Interval" label text next to the input.
- Fixed slideshow controls being pushed off-screen on mobile by using
  100dvh (dynamic viewport height) with 100vh as a fallback, so the
  layout accounts for mobile browser chrome.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/public/js/slideshow.js b/public/js/slideshow.js
index d1a0a95..ddcaa3c 100644
--- a/public/js/slideshow.js
+++ b/public/js/slideshow.js
@@ -203,6 +203,10 @@ const ssParams = new URLSearchParams(location.search);
 if (ssParams.get('shuffle') === '1') {
   ssQueue = shuffle(SS_ENTRIES);
 }
+const ivParam = parseFloat(ssParams.get('interval'));
+if (ivParam >= 1 && ivParam <= 60) {
+  document.getElementById('ss-interval').value = ivParam;
+}
 
 if (ssQueue.length > 0) {
   ssShow(0, true);