feat(imaging): default to pure-Rust codecs

api/SEMVER-AUDIT.md

@@ -46,7 +46,7 @@ The exact mapping, exported-marker, feature, and normalized Rust declaration has
 - .NET events become `subscribe_*` calls returning an owned `Subscription`; callbacks are `Send + Sync` and dispatch outside internal locks.
 - `IDisposable` becomes explicit idempotent shutdown plus `Drop`; cancellation remains a typed `Error::Cancelled`.
 - Closed C# enums retain fixed discriminants and are SemVer-breaking to extend; flags retain unknown bits, while public Rust error enums are `non_exhaustive`.
-- Optional native and pure-Rust backends remain feature-gated (`jpeg2000`, `rust-j2k`, `skia`, `rust-skia`, `vorbis`, `real-audio`); default and empty-default sets are part of the baseline.
+- Pure-Rust image backends are enabled by default (`rust-j2k`, `rust-skia`); native alternatives remain feature-gated (`jpeg2000`, `skia`, `vorbis`, `real-audio`), and empty-default sets remain part of the baseline.
 - Capability HTTP injection uses project-owned `HttpMessageHandler`, `CapsHttpLimits`, and `with_native_transport`; the internal `reqwest` client is not part of the public surface.
 - External C# signature types map to core/std, adopted cross-platform crates, or project-owned boundary types; no third-party crate path leaks through mapped signatures or public Rust declarations.
 

api/SEMVER-BASELINE.json

@@ -30,7 +30,8 @@
           "dep:bcdec_rs"
         ],
         "default": [
-          "dds-bc67"
+          "dds-bc67",
+          "rust-j2k"
         ],
         "jpeg2000": [
           "libremetaverse-imaging/jpeg2000"
@@ -69,7 +70,9 @@
       "name": "libremetaverse-imaging",
       "version": "0.0.1",
       "features": {
-        "default": [],
+        "default": [
+          "rust-j2k"
+        ],
         "jpeg2000": [
           "dep:libremetaverse-openjpeg"
         ],
@@ -86,7 +89,9 @@
       "name": "libremetaverse-imaging-skia",
       "version": "0.0.1",
       "features": {
-        "default": [],
+        "default": [
+          "rust-skia"
+        ],
         "rust-skia": [
           "dep:image-webp",
           "dep:skia-rs-codec",