buildPrompt method presentation ✓ 100.0%

  buildPrompt(input: FieldClassifierInput): string {
    const base = renderPromptBase(this);
    const sections: string[] = [];

    // Element HTML (truncated for token economy)
    const html =
      input.elementHtml.length > MAX_ELEMENT_HTML_CHARS
        ? input.elementHtml.slice(0, MAX_ELEMENT_HTML_CHARS) + "…"
        : input.elementHtml;
    sections.push(`=== Element HTML ===\n${html}`);

    // Surrounding container HTML
    if (input.contextHtml) {
      const ctx =
        input.contextHtml.length > MAX_CONTEXT_HTML_CHARS
          ? input.contextHtml.slice(0, MAX_CONTEXT_HTML_CHARS) + "…"
          : input.contextHtml;
      sections.push(`=== Surrounding HTML ===\n${ctx}`);
    }

    // Pre-computed text signals
    if (input.signals?.trim()) {
      sections.push(`=== Field Signals ===\n${input.signals}`);
    }

    return `${base}\n\nClassify this form field:\n\n${sections.join("\n\n")}`;
  },