add screencast (#67)

* docs

* updates

* Fix: The handleCopy function fails to handle errors from navigator.clipboard.writeText(), causing unhandled exceptions and misleading UI feedback when clipboard operations fail.

Co-authored-by: ctate <chris@ctate.dev>

* Fix: The benchmark file uses emojis (📊, 🚀, 🔨, 📈, 📋, ✅, ⏱️, ⚠) in console output, violating repository guidelines that forbid emojis in code and output.

Co-authored-by: ctate <chris@ctate.dev>

* Remove benchmark/run.ts from PR

* screencast

* update docs

* address comments

---------

Co-authored-by: Vercel <vercel[bot]@users.noreply.github.com>

cli/src/output.rs

@@ -1198,6 +1198,11 @@ Options:
   --cdp <port>               Connect via CDP (Chrome DevTools Protocol)
   --debug                    Debug output
 
+Environment:
+  AGENT_BROWSER_SESSION          Session name (default: "default")
+  AGENT_BROWSER_EXECUTABLE_PATH  Custom browser executable path
+  AGENT_BROWSER_STREAM_PORT      Enable WebSocket streaming on port (e.g., 9223)
+
 Examples:
   agent-browser open example.com
   agent-browser snapshot -i              # Interactive elements only