implemented tag cloud

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

frontend/src/routes/tags/Index.svelte

@@ -0,0 +1,40 @@
+<script>
+    import { useTinyRouter } from 'svelte-tiny-router';
+    import { onMount }       from 'svelte';
+    import { api }           from '../../urls.svelte';
+    import { error, yikes }  from '../../warn.svelte';
+    import { t }             from '../../translations.svelte';
+
+    let router = useTinyRouter();
+    let tags = $state(null);
+
+    function onclick(e){
+        e.preventDefault();
+        var target = e.target;
+        while (target && !target.href) target=target.parentNode;
+        let href = target.getAttribute('href');
+        if (href) router.navigate(href);
+        return false;
+    }
+
+    async function loadTags(){
+        const url = api('tags');
+        const res = await fetch(url,{credentials:'include'});
+        if (res.ok){
+            yikes();
+            tags = await res.json();
+        } else error(res);
+    }
+
+    onMount(loadTags)
+</script>
+
+<h1>{t('tags')}</h1>
+
+<div class="cloud">
+{#if tags}
+{#each tags as entry}
+<a href="/tags/use/{encodeURIComponent(entry.tag)}" class="tag" style="font-size: {40 - 28/entry.count}px" title={t('count_of_occurrences',entry)} {onclick} >{entry.tag}</a>
+{/each}
+{/if}
+</div>