fix(browser): prevent const redeclaration in evaluateWithArgs

[lw-yang]

Summary

• evaluateWithArgs now wraps its generated const declarations in an IIFE instead of emitting them as bare top-level statements
• Fixes SyntaxError: Identifier 'markerAttr' has already been declared when multiple browser commands run in sequence on the same page

Problem

Chrome's Runtime.evaluate shares a single global execution context per page. Top-level const declarations persist across calls. When two methods both inject the same variable name via evaluateWithArgs (e.g. markerAttr in tryCdpOnResolvedElement and uploadFile), the second call fails:

SyntaxError: Identifier 'markerAttr' has already been declared

Reproducer: any opencli browser <session> upload <ref> file.png command — it calls click resolution (which injects markerAttr) then upload (which also injects markerAttr).

Fix

Wrap the generated code in an IIFE so const declarations are function-scoped:

// Before (leaks into global context)
return this.evaluate(`${declarations}\n${js}`);

// After (scoped to IIFE)
return this.evaluate(`(() => { ${declarations}\nreturn (${js}); })()`);

Test plan

• Added 2 unit tests verifying IIFE wrapping and safe repeated-name usage
• All 41 existing tests pass (vitest run --project unit src/browser/base-page.test.ts)
• Manually verified: opencli browser <s> upload now works on xiaohongshu creator center (was 100% repro before fix)

🤖 Generated with Claude Code