fix: use JSON.stringify for safe JS string interpolation in evaluate() (#109)

Replace ad-hoc string escaping with JSON.stringify() for values
interpolated into JavaScript code strings passed to page.evaluate().

- explore.ts: clickLabels were escaped with only single-quote
  replacement, which breaks on labels containing backslashes or
  newlines. JSON.stringify() handles all edge cases correctly.

- synthesize.ts: buildEvaluateScript() embedded URLs directly inside
  single quotes. JSON.stringify() safely handles URLs containing
  special characters.

src/explore.ts

@@ -250,11 +250,11 @@ export async function exploreUrl(
            // First: targeted clicks by label (e.g. "字幕", "CC", "评论")
            if (opts.clickLabels?.length) {
              for (const label of opts.clickLabels) {
-               const safeLabel = label.replace(/'/g, "\\'");
+               const safeLabel = JSON.stringify(label);
                await page.evaluate(`
                  (() => {
                    const el = [...document.querySelectorAll('button, [role="button"], [role="tab"], a, span')]
-                     .find(e => e.textContent && e.textContent.trim().includes('${safeLabel}'));
+                     .find(e => e.textContent && e.textContent.trim().includes(${safeLabel}));
                    if (el) el.click();
                  })()
                `);

src/synthesize.ts

@@ -116,7 +116,7 @@ function buildEvaluateScript(url: string, itemPath: string, endpoint: any): stri
 
   return [
     '(async () => {',
-    `  const res = await fetch('${url}', {`,
+    `  const res = await fetch(${JSON.stringify(url)}, {`,
     `    credentials: 'include'`,
     '  });',
     '  const data = await res.json();',