feat(post): post actions toolbar (share / copy / print / reading time)

Adds a small toolbar next to the comment-count badge with four actions:

- Share — uses `navigator.share()` on supporting devices, falls back
  to copy-link otherwise
- Copy link — clipboard API with `<input>` + `execCommand` fallback,
  flashes a checkmark for 1.5s on success
- Print — `window.print()`, hidden via `print:hidden` so it doesn't
  show up in the printed output itself
- Reading time — server-computed from headline+body HTML at ~200 wpm,
  hidden when 0

Reading time + canonical URL come from `+page.server.ts` so SSR
output is identical and shareable URLs render correctly.

All labels go through the translations layer (5 new
`post_action_*` keys).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/lib/components/PostActions.svelte

@@ -0,0 +1,120 @@
+<script lang="ts">
+  import Icon from "@iconify/svelte";
+  import "$lib/iconify-offline";
+  import { useTranslate, T } from "$lib/translations";
+
+  let {
+    url,
+    title,
+    readingTimeMinutes = null,
+    class: cls = "",
+  }: {
+    /** Absolute URL of the page being shared. */
+    url: string;
+    /** Page headline — used by the native share-sheet. */
+    title: string;
+    /** Estimated reading time. `null` hides the badge. */
+    readingTimeMinutes?: number | null;
+    class?: string;
+  } = $props();
+
+  const t = useTranslate();
+
+  let copied = $state(false);
+  let shared = $state(false);
+  let copyTimer: ReturnType<typeof setTimeout> | null = null;
+  let shareTimer: ReturnType<typeof setTimeout> | null = null;
+
+  function flashCopied() {
+    copied = true;
+    if (copyTimer) clearTimeout(copyTimer);
+    copyTimer = setTimeout(() => (copied = false), 1500);
+  }
+
+  function flashShared() {
+    shared = true;
+    if (shareTimer) clearTimeout(shareTimer);
+    shareTimer = setTimeout(() => (shared = false), 1500);
+  }
+
+  async function copyLink() {
+    try {
+      await navigator.clipboard.writeText(url);
+      flashCopied();
+    } catch {
+      // Fallback: temporary <input> + execCommand for older browsers.
+      const el = document.createElement("input");
+      el.value = url;
+      document.body.appendChild(el);
+      el.select();
+      try {
+        document.execCommand("copy");
+        flashCopied();
+      } catch {
+        // give up — clipboard not available
+      } finally {
+        el.remove();
+      }
+    }
+  }
+
+  async function share() {
+    const w = window as unknown as { navigator: Navigator & { share?: (data: ShareData) => Promise<void> } };
+    if (typeof w.navigator.share === "function") {
+      try {
+        await w.navigator.share({ title, url });
+        flashShared();
+        return;
+      } catch {
+        // user cancelled or share failed → fall through to copy
+      }
+    }
+    await copyLink();
+  }
+
+  function print() {
+    window.print();
+  }
+</script>
+
+<div class="inline-flex flex-wrap items-center gap-x-2 gap-y-1 {cls}">
+  <button
+    type="button"
+    onclick={share}
+    class="inline-flex items-center gap-1 text-xs font-medium text-zinc-600 hover:text-zinc-900 transition-colors"
+    aria-label={t(T.post_action_share)}
+  >
+    <Icon icon={shared ? "mdi:check" : "mdi:share-variant-outline"} class="size-4" />
+    <span class="hidden sm:inline">{shared ? t(T.post_action_copied) : t(T.post_action_share)}</span>
+  </button>
+
+  <button
+    type="button"
+    onclick={copyLink}
+    class="inline-flex items-center gap-1 text-xs font-medium text-zinc-600 hover:text-zinc-900 transition-colors"
+    aria-label={t(T.post_action_copy)}
+  >
+    <Icon icon={copied ? "mdi:check" : "mdi:link-variant"} class="size-4" />
+    <span class="hidden sm:inline">{copied ? t(T.post_action_copied) : t(T.post_action_copy)}</span>
+  </button>
+
+  <button
+    type="button"
+    onclick={print}
+    class="inline-flex items-center gap-1 text-xs font-medium text-zinc-600 hover:text-zinc-900 transition-colors print:hidden"
+    aria-label={t(T.post_action_print)}
+  >
+    <Icon icon="mdi:printer-outline" class="size-4" />
+    <span class="hidden sm:inline">{t(T.post_action_print)}</span>
+  </button>
+
+  {#if readingTimeMinutes != null && readingTimeMinutes > 0}
+    <span
+      class="inline-flex items-center gap-1 text-xs text-zinc-500"
+      title={t(T.post_action_reading_time, { minutes: readingTimeMinutes })}
+    >
+      <Icon icon="mdi:clock-outline" class="size-4" />
+      <span class="tabular-nums">{t(T.post_action_reading_time, { minutes: readingTimeMinutes })}</span>
+    </span>
+  {/if}
+</div>