fix(render): recover orphaned browsers before retry

[miguel-heygen]

Summary

• run the existing scoped orphan-browser recovery before every local render
• report how many stale browser trees were reclaimed before a retry
• add regression coverage at the local-render boundary

Reproduction

On hyperframes@0.7.56, start a long single-worker render and hard-kill the CLI Node process during capture_streaming. Five chrome-headless-shell processes remained alive after five seconds, reparented outside the dead CLI tree. This matches the WSL report where an external 600-second timeout left Chrome children consuming swap.

The orphan cleanup introduced for preview in #1039 was never called by the standalone render path. This change reuses that current-user, PPID=1-scoped cleanup at the beginning of renderLocal, so the next render automatically recovers from a hard-killed predecessor.

Verification

• bunx vitest run packages/cli/src/commands/render.test.ts packages/cli/src/utils/orphanCleanup.test.ts (59 passed)
• targeted oxlint and oxfmt checks
• pre-commit typecheck, tracked-artifact, lint, format, and fallow gates
• git diff --check