feat: proper in-page reveal mode + privacy note

Reveal mode (eye icon) now works as intended:
- Toggle ON: all existing responses on the page get fake→real
  substitution applied immediately (paths, names, emails, etc.)
- Streaming responses are revealed in real-time as they arrive
- Toggle OFF: original text is restored from saved state
- Covers code blocks, artifacts, pre tags, and all response
  containers across all supported services
- Blue floating badge shows "Reveal Mode — showing real data"
  when active so user knows what they're seeing

The workflow is now: type /home/jsmith/... → Claude sees
/home/ademo/... → Claude responds with /home/ademo/... →
reveal mode shows /home/jsmith/... → user copies real path.

Also adds privacy note in popup footer: data stays in local
browser storage, no servers, no tracking, no analytics.

https://claude.ai/code/session_01Dvgwe7XMoSxnWXkih8p1Cw

src/content/content.css

@@ -20,3 +20,28 @@
   border-radius: 2px;
   padding: 0 1px;
 }
+
+/* Floating reveal mode indicator */
+.ss-reveal-badge {
+  position: fixed;
+  bottom: 16px;
+  right: 16px;
+  background: #1d4ed8;
+  color: #fff;
+  padding: 6px 14px;
+  border-radius: 20px;
+  font-size: 12px;
+  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
+  font-weight: 500;
+  z-index: 999999;
+  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
+  pointer-events: none;
+  opacity: 0;
+  transform: translateY(10px);
+  transition: opacity 0.2s, transform 0.2s;
+}
+
+.ss-reveal-badge.visible {
+  opacity: 1;
+  transform: translateY(0);
+}