Add Share on X button after review completes

Opens Twitter's share intent with a pre-filled post containing the
review mode, trimmed verdicts, and app URL. Button appears alongside
the Copy button only after streaming finishes.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

public/app.js

@@ -14,6 +14,7 @@ const tabButtons = document.querySelectorAll(".tab");
 const brutalityBtns = document.querySelectorAll(".brutality-btn");
 const issueBadge = document.getElementById("issue-badge");
 const copyBtn = document.getElementById("copy-btn");
+const shareXBtn = document.getElementById("share-x-btn");
 const toast = document.getElementById("toast");
 
 const GITHUB_BLOB_RE = /^https?:\/\/github\.com\/[^/]+\/[^/]+\/blob\/[^/]+\/.+$/;
@@ -239,6 +240,31 @@ function renderIssueBadge(counts) {
   issueBadge.hidden = false;
 }
 
+/* --- Share on X --- */
+
+function stripMarkdown(md) {
+  return md.replace(/\*\*/g, "").replace(/^#+\s*/gm, "").replace(/\n{2,}/g, "\n").trim();
+}
+
+function shareOnX() {
+  const url = urlInput.value.trim();
+  const mode = brutalityLevel;
+  const verdicts = stripMarkdown(currentSections.verdicts || "");
+
+  const header = `I reviewed code with Arcee AI Trinity Large in ${mode} mode and here's what Linus, Knuth, and Bjarne had to say:\n\n`;
+  const footer = `\n\nTry it yourself: https://huggingface.co/spaces/julien-c/trinity-large\n${url}`;
+  const maxVerdicts = 280 - header.length - footer.length;
+  const trimmedVerdicts = verdicts.length > maxVerdicts
+    ? verdicts.slice(0, maxVerdicts - 1) + "\u2026"
+    : verdicts;
+
+  const text = header + trimmedVerdicts + footer;
+  const shareUrl = `https://twitter.com/intent/tweet?text=${encodeURIComponent(text)}`;
+  window.open(shareUrl, "_blank", "width=600,height=400");
+}
+
+shareXBtn.addEventListener("click", shareOnX);
+
 /* --- Copy to clipboard --- */
 
 function buildMarkdownExport() {
@@ -319,6 +345,7 @@ function startReview() {
   });
   issueBadge.hidden = true;
   copyBtn.hidden = true;
+  shareXBtn.hidden = true;
   fullMarkdown = "";
 
   if (!url) { showInputError("Please enter a GitHub file URL."); return; }
@@ -363,6 +390,7 @@ function startReview() {
     const counts = countIssuePriorities(markdown);
     renderIssueBadge(counts);
     copyBtn.hidden = false;
+    shareXBtn.hidden = false;
   });
 
   source.addEventListener("error", (e) => {

public/index.html

@@ -267,6 +267,11 @@
         <button class="tab" data-section="security">Security</button>
         <button class="tab" data-section="suggestions">Suggestions</button>
         <button class="tab" data-section="verdicts">Verdicts</button>
+        <button type="button" id="share-x-btn" hidden title="Share on X">
+          <svg viewBox="0 0 24 24" width="16" height="16" fill="currentColor">
+            <path d="M18.244 2.25h3.308l-7.227 8.26 8.502 11.24H16.17l-5.214-6.817L4.99 21.75H1.68l7.73-8.835L1.254 2.25H8.08l4.713 6.231zm-1.161 17.52h1.833L7.084 4.126H5.117z"/>
+          </svg>
+        </button>
         <button type="button" id="copy-btn" hidden>Copy Review</button>
       </nav>
       <div id="tab-content" class="tab-content"></div>

public/style.css

@@ -493,10 +493,34 @@ h1 {
   color: var(--text-muted);
 }
 
+/* ---------- Share on X Button ---------- */
+
+#share-x-btn {
+  margin-left: auto;
+  padding: 6px 10px;
+  color: var(--text-muted);
+  background: var(--surface);
+  border: 1px solid var(--border);
+  border-radius: var(--radius);
+  cursor: pointer;
+  transition: all 0.15s;
+  display: inline-flex;
+  align-items: center;
+}
+
+#share-x-btn:hover {
+  color: var(--text);
+  border-color: var(--accent);
+}
+
+#share-x-btn:active {
+  background: var(--accent);
+  color: #fff;
+}
+
 /* ---------- Copy Button ---------- */
 
 #copy-btn {
-  margin-left: auto;
   padding: 6px 14px;
   font-size: 0.82rem;
   font-weight: 500;