feat(ts): generate <Proto>Client / dispatcher against @comline/runtime - #8

The TypeScript `code` generator now emits the full RPC shape for a
`protocol`, not just the method signatures:

  - `error <Name>` -> `export interface <Name>` (wire payload) + `export
    class <Name>Error extends Error` carrying `.data` and a static
    `.ordinal` (the throwable a provider raises / a client re-raises).
  - `<Proto><Fn>Params` interface per function with arguments.
  - `<Proto>` provider interface: `Promise`-returning methods, `@throws
    {<Name>Error}` JSDoc.
  - `<PROTO>_CALLS` const table.
  - `<Proto>Dispatcher implements Dispatch` — decode params, run the impl,
    map a caught `<Name>Error` to `reply.err(ordinal, ...)`, one-way calls
    leave the reply empty.
  - `<Proto>Client` + static `connect()` (runs the handshake from
    `IR_HASH`): one method per function, decoding the `Envelope`, mapping
    `env.err.id` back to `<Name>Error` or `RuntimeError.remote`.
  - `serve<Proto>(impl, transport, codec, framing?)` helper.

Framing follows `@framing` on the protocol / the package `default_framing`
(same recognition set as the Rust generator): `DatagramFraming` default,
`JsonRpcFraming` for `jsonrpc`.

`runtime/test/generated/chat.ts` is real generator output (blessed by
`generate.rs`, `TS_BLESS=1` to refresh); `runtime/test/generated.test.ts`
type-checks it and runs a client ⇆ provider round-trip over `duplex()`.