fix(a11y): improve img alt text with artist/director/author context

Updates alt attributes to include contextual info: songs include artist,
films include year and director, books include author, TV series include
type label.

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

packages/app/src/components/content/BookGrid.vue

@@ -57,7 +57,7 @@
               <img
                 v-if="coverSrc(book)"
                 :src="coverSrc(book)!"
-                :alt="book.title"
+                :alt="`${book.title} by ${book.author}`"
                 class="w-full h-full object-cover transition-transform duration-300 group-hover:scale-110"
                 loading="lazy"
                 @error="onCoverError(book)"

packages/app/src/components/content/FilmGrid.vue

@@ -57,7 +57,7 @@
               <img
                 v-if="coverSrc(film)"
                 :src="coverSrc(film)!"
-                :alt="film.title"
+                :alt="`${film.title} (${film.year}) directed by ${film.director}`"
                 class="w-full h-full object-cover transition-transform duration-300 group-hover:scale-110"
                 loading="lazy"
                 @error="onCoverError(film)"

packages/app/src/components/content/SongGrid.vue

@@ -68,7 +68,7 @@
               <img
                 v-if="coverSrc(song)"
                 :src="coverSrc(song)!"
-                :alt="song.title"
+                :alt="`${song.title} by ${song.artist}`"
                 class="w-full h-full object-cover transition-transform duration-300 group-hover:scale-110"
                 loading="lazy"
                 @error="onCoverError(song)"

packages/app/src/components/content/TVSeriesGrid.vue

@@ -57,7 +57,7 @@
               <img
                 v-if="coverSrc(s)"
                 :src="coverSrc(s)!"
-                :alt="s.title"
+                :alt="`${s.title} — TV Series`"
                 class="w-full h-full object-cover transition-transform duration-300 group-hover:scale-110"
                 loading="lazy"
                 @error="onCoverError(s)"