feat(04-03): create TagInput component and integrate into EntryCard

- Create TagInput.svelte with Svelecte for multi-select autocomplete
- Support creating new tags inline via creatable mode
- Display tags on collapsed entry cards (max 3 with +N indicator)
- Add TagInput in expanded view for editing entry tags
- Pass availableTags through EntryList to EntryCard
- Handle tag changes with immediate save via updateTags action

src/routes/+page.svelte

@@ -42,7 +42,7 @@
 	</header>
 
 	<div class="max-w-2xl mx-auto px-4 py-4">
-		<EntryList entries={data.entries} />
+		<EntryList entries={data.entries} availableTags={data.allTags} />
 	</div>
 
 	<QuickCapture />