fix(open): preserve returned tab ids

[MonkeyLeeT]

Summary

• preserve string tab ids for bb-browser open --tab, including short ids, full CDP target ids, and numeric-looking short ids
• make open --tab current navigate the active/current daemon target instead of resolving current as a literal tab id
• prefer the short tab id in human open output while still showing the full target id separately
• fix the fallback short id for newly opened tabs
• add CLI and daemon regressions for the tab-targeting contract, including using returned open ids in a follow-up eval request

Scope

This PR keeps the open lifecycle behavior unchanged: new tabs are still created in the background and open does not wait for page readiness. It only fixes the tab id contract so returned ids and explicit --tab values stay usable by the daemon resolver.

Root cause

The CLI parsed open --tab as a number, which rejected full CDP target ids and could turn numeric-looking short ids into tab indexes. The daemon also treated current as an ordinary tab reference before the open handler had a chance to navigate the current tab.

Validation

• pnpm --filter @bb-browser/cli test
• pnpm --filter @bb-browser/daemon test
• pnpm build
• pnpm lint
• pre-commit hook ran pnpm build and pnpm test
• synthetic merge-tree with fix(daemon): activate tabs before mouse input #212 keeps a single activation helper and no open lifecycle changes

Refs #195