Add open --relaunch and persist replay semantics

[thymikee]

Summary:

• add a new --relaunch flag for open to force app process restart before launch
• wire relaunch behavior in session open handling (close then open)
• persist relaunch in recorded session actions and serialize/parse it in .ad replay scripts
• document and parse the new flag in CLI args/help
• add unit tests for args parsing, relaunch session flow, session log output, and replay parsing

Verification:

• pnpm typecheck
• pnpm test:unit
• pnpm test:smoke

[github-actions]

PR Preview Action v1.8.1
🚀 View preview at https://callstackincubator.github.io/agent-device/pr-preview/pr-52/
Built to branch gh-pages at 2026-02-13 18:08 UTC. Preview will be ready when the GitHub Pages deployment is complete.