fix: allow SessionStart hook more time to restore state

[Hughhhhcoder]

Summary

• increase the Codex SessionStart hook timeout from 5 seconds to 60 seconds
• add a manifest-level regression test so the timeout does not regress

Fixes #670.

Validation

• npm test (92 passed)
• npx tsc -p tsconfig.app-server.json --noEmit
• python3 -m json.tool plugins/codex/hooks/hooks.json
• git diff --check

npm run build could not run because the local prebuild command resolves a missing global Codex binary (codex app-server generate-ts, ENOENT).

[Hughhhhcoder]

Status update: the current head remains 592b7ac7f1a93545922cad04edbe1bd49f8da9df; local npm test passed (91 tests) and tsc -p tsconfig.app-server.json --noEmit passed. GitHub Pull Request CI is currently action_required with zero jobs, so maintainer approval is needed before CI can run. The full build remains locally blocked only by the prebuild dependency on a global codex app-server generate-ts binary.