fix(build): activated zune-jpeg log feature and widened test compat type

- zune-jpeg 0.5.15 (image 0.25's JPEG decoder) cannot compile with its
  non-default log feature off: zune-core's no-log warn! stub is not
  expression-safe. A feature-activation-only workspace dep on
  zune-jpeg { features = ["log"] } fixes the cold build; log stays 0.4.33.
- model-registry-default-config's local ModelSnapshot type gains the optional
  streamIdleTimeoutMs the Bedrock watchdog compat now emits.

Cargo.toml

@@ -317,6 +317,10 @@ image = { version = "0.25", default-features = false, features = [
    "gif",
    "webp",
 ] }
+# Not used directly: activates zune-jpeg's non-default `log` feature so image's
+# JPEG decoder compiles — zune-jpeg 0.5.15's no-log stub macros are not
+# expression-safe and the crate fails to build without it.
+zune-jpeg = { version = "0.5", default-features = false, features = ["log"] }
 png = "0.18"
 inferno = { version = "0.12", default-features = false }
 syntect = { version = "5.3", default-features = false, features = [