Zod v4's object parser compiles a fast path with `new Function()`, which
violates CSP without `unsafe-eval`. Hosts that enforce the spec's default
CSP (e.g. VS Code) cannot load any View that parses an incoming message —
the SDK's generated schemas trip this on the very first ui/initialize
roundtrip.
The App constructor now sets `z.config({ jitless: true })` by default so
Views work out of the box under strict CSP. New `AppOptions.allowUnsafeEval`
(default false) skips this for Views that know their host permits
`unsafe-eval` and want Zod's faster JIT path.
Addresses #374. Also relevant to #199 (threejs-server has a separate
`new Function()` use in its own shader compiler that this does not fix).