dev-0.43.1-rc.297

fix(openclaw): handle exit code 3 from rtk rewrite

Interpret all RTK rewrite exit codes and respond appropriately:
- Exit 0 (Allow): auto-apply rewrite
- Exit 1 (Passthrough): no RTK equivalent, pass through unchanged
- Exit 2 (Deny): block the call entirely
- Exit 3 (Ask): rewrite available, require user approval via
  requireApproval with allow-once/deny decisions

Uses execFileSync (not execSync) to avoid shell injection. Returns
a [string | null, RewriteVerdict?] tuple from tryRewrite so the
before_tool_call hook can react to each verdict type.

"allow-always" omitted from allowedDecisions because OpenClaw does
not auto-persist approval for plugin hooks — see:
https://docs.openclaw.ai/plugins/plugin-permission-requests#troubleshooting

Closes #2202