fix: strip HTML-encoded tags (decode entities before stripping)

The previous stripHtml decoded </> after the regex pass, so content
stored as <p>text</p> was never stripped. Now entities are
decoded first, then all tags are removed.

Also strip HTML when prefilling compose from an existing post (Edit/Repost)
so the text field shows clean content, not raw markup.

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

artifacts/postiz-mobile/app/(tabs)/posts.tsx

@@ -155,7 +155,7 @@ export default function PostsScreen() {
     router.push({
       pathname: "/(tabs)/compose",
       params: {
-        prefillContent: post.content,
+        prefillContent: stripHtml(post.content),
         prefillIntegrationIds: integrations.map((i) => i.id).join(","),
       },
     });

artifacts/postiz-mobile/lib/stripHtml.ts

@@ -1,14 +1,19 @@
 export function stripHtml(html: string): string {
-  return html
+  // Decode entities first so encoded tags like <p> are also stripped
-    .replace(/<br\s*\/?>/gi, "\n")
+  let s = html
-    .replace(/<\/p>/gi, "\n")
-    .replace(/<[^>]+>/g, "")
     .replace(/&amp;/g, "&")
     .replace(/&lt;/g, "<")
     .replace(/&gt;/g, ">")
     .replace(/&quot;/g, '"')
     .replace(/&#39;/g, "'")
-    .replace(/&nbsp;/g, " ")
+    .replace(/&nbsp;/g, " ");
-    .replace(/\n{3,}/g, "\n\n")
+  // Block-level tags → newlines
-    .trim();
+  s = s
+    .replace(/<br\s*\/?>/gi, "\n")
+    .replace(/<\/p>/gi, "\n")
+    .replace(/<\/div>/gi, "\n")
+    .replace(/<\/li>/gi, "\n");
+  // Strip all remaining tags
+  s = s.replace(/<[^>]+>/g, "");
+  return s.replace(/\n{3,}/g, "\n\n").trim();
 }