Function flashElements

packages/core/src/runtime/bridge.ts:98–128

* Flash elements — briefly highlight them with a blue outline. * Used by the chat-canvas bridge to show what changed after an agent edit.

(selectors: string[], duration: number)

 * Used by the chat-canvas bridge to show what changed after an agent edit.
 */
function flashElements(selectors: string[], duration: number): void {
  if (!document.getElementById("__hf-flash-styles")) {
    const style = document.createElement("style");
    style.id = "__hf-flash-styles";
    style.textContent = `
      .__hf-flash {
        outline: 2px solid rgba(59, 130, 246, 0.6) !important;
        outline-offset: 2px !important;
        animation: __hf-flash-pulse ${duration}ms ease-out forwards !important;
      }
      @keyframes __hf-flash-pulse {
        0% { outline-color: rgba(59, 130, 246, 0.8); }
        100% { outline-color: transparent; }
      }
    `;
    document.head.appendChild(style);
  }

  for (const selector of selectors) {
    try {
      const els = document.querySelectorAll(selector);
      els.forEach((el) => {
        el.classList.add("__hf-flash");
        setTimeout(() => el.classList.remove("__hf-flash"), duration);
      });
    } catch (err) {
      // Invalid selector — skip
      swallow("bridge.flashElements.querySelector", err);
    }
  }
}