feat: add floating feedback button for better visibility

Adds a fixed-position FAB (bottom-right) with speech bubble icon that
links to GitHub Issues with prefilled template. Footer link remains as
secondary access point.

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

Author: rdmueller

src/components/RiskRadar.jsx

@@ -134,6 +134,10 @@ export default function RiskRadar() {
         </div>
       </div>
 
+      <a href={`https://github.com/LLM-Coding/vibe-coding-risk-radar/issues/new?title=${encodeURIComponent(t.footer.feedbackTitle)}&body=${encodeURIComponent(t.footer.feedbackBody)}`} target="_blank" rel="noopener" className={styles.fab}>
+        <span className={styles.fabIcon}>💬</span> {t.footer.feedback}
+      </a>
+
       <DocSidebar docs={t.docs} open={docsOpen} onClose={() => setDocsOpen(false)} />
     </div>
   );

src/components/RiskRadar.module.css

@@ -214,3 +214,35 @@
 .footerLink {
   color: var(--text-secondary);
 }
+
+.fab {
+  position: fixed;
+  bottom: 24px;
+  right: 24px;
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  background: var(--bg-card);
+  border: 1px solid var(--border);
+  border-radius: 24px;
+  padding: 10px 14px;
+  font-size: 14px;
+  font-weight: 600;
+  color: var(--text-secondary);
+  cursor: pointer;
+  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
+  transition: all 0.2s;
+  text-decoration: none;
+  z-index: 50;
+}
+
+.fab:hover {
+  color: var(--text-heading);
+  border-color: var(--text-secondary);
+  box-shadow: 0 4px 16px rgba(0,0,0,0.2);
+}
+
+.fabIcon {
+  font-size: 18px;
+  line-height: 1;
+}