feat(cli): let projects opt out of automatic proxying (#2591)

* feat(studio-server): serve H.264 proxies from the preview route

Wires the codec manifest and the transcoder into the preview surface: the route
negotiates a proxy via a query param and serves it through the existing range
and ETag machinery, composition HTML carries a codec map for the runtime, and
hostile assets pre-warm so a first play does not wait on a cold transcode.
Exposes the three subpath exports the CLI surfaces consume upstack.

Drops the TEMP fallow entry added with the transcoder: it has real importers now.

* fix(studio-server): publish media proxy exports

* fix(parsers): scan HTML comments linearly

* feat(cli): let projects opt out of automatic proxying

Adds media.autoProxy to hyperframes.json plus --proxy/--no-proxy flags, and
forwards the resolved value into the studio and preview servers and the vite
adapter. Lands before the runtime slice that turns auto-proxying on, so the
switch exists before there is any behavior to switch off.

* fix(cli): align media config schema

packages/cli/src/utils/studioProxyEnv.ts

@@ -0,0 +1,9 @@
+export function studioProxyEnv(
+  autoProxy: boolean,
+  baseEnv: NodeJS.ProcessEnv = process.env,
+): NodeJS.ProcessEnv {
+  return {
+    ...baseEnv,
+    HYPERFRAMES_AUTO_PROXY: autoProxy ? "true" : "false",
+  };
+}