#267: jump to top/bottom buttons for long pastes and the editor

Fixed-position Top/Bottom pills appear only when content exceeds 2x
viewport height (window scroll on paste view, textarea scroll on /new).
New static/jump.js drives them; markup added to paste.html and new.html.

internal/web/static/app.css

@@ -884,3 +884,17 @@ button[type="submit"]:focus-visible,
 .created-banner { display: block; }
 /* #167: gutter rows for wrapped paste view — one row per visual code line */
 .gutline { display: block; }
+
+/* #267: jump to top/bottom pills for long pastes and the editor.
+   Hidden unless JS (jump.js) detects content more than 2x the viewport. */
+.jumpnav {
+  position: fixed;
+  right: 18px;
+  bottom: 18px;
+  z-index: 50;
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+.jumpnav.hidden { display: none; }
+.jump-btn { box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25); }