feat(view): standing input and names for the P1 project (운곡교P1 · 운곡교)

- The sample button and ?sample=1 fill the project name 운곡교P1 and the bridge
  name 운곡교. The sample is RAG/운곡교P1입력.xlsx.
- Test: the app's copy stays byte-identical to the RAG file (skipped when the
  RAG folder is absent) and reads one pier, P1, T형, 말뚝기초, 10 bearings.

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>

src/main.ts

@@ -1170,9 +1170,18 @@ $<HTMLInputElement>('file').addEventListener('change', async (ev) => {
     setStatus(`엑셀을 읽지 못했습니다: ${(err as Error).message}`);
   }
 });
+/** The project's standing input and names (RAG/운곡교P1입력.xlsx → 프로젝트 운곡교P1, 교량 운곡교). */
+const SAMPLE_PROJECT = { name: '운곡교P1', bridge: '운곡교' } as const;
+
+function fillSampleNames(): void {
+  $<HTMLInputElement>('project-name').value = SAMPLE_PROJECT.name;
+  $<HTMLInputElement>('bridge-name').value = SAMPLE_PROJECT.bridge;
+}
+
 $<HTMLButtonElement>('pick-sample').addEventListener('click', async () => {
   try {
     loadBytes(await fetchSample(), '샘플 P1 (운곡교P1입력.xlsx)');
+    fillSampleNames();
   } catch (err) {
     setStatus(`샘플을 불러오지 못했습니다: ${(err as Error).message}`);
   }
@@ -1251,8 +1260,7 @@ if (new URLSearchParams(window.location.search).get('sample') === '1') {
   fetchSample()
     .then((bytes) => {
       loadBytes(bytes, '샘플 P1');
-      $<HTMLInputElement>('project-name').value = '운곡교 P1 샘플';
-      $<HTMLInputElement>('bridge-name').value = '운곡교';
+      fillSampleNames();
       applyImport();
     })
     .catch((err: Error) => setStatus(`샘플을 불러오지 못했습니다: ${err.message}`));