core: merge oak-common into oak-core

oak-common is gone; its modules (configstore, xmlutils, ocioutils,
oiioutils, colormath, colortransform, videoparams, ffmpegutils, ...)
now live in oak-core alongside the value types. The render value/GPU
types moved too: backend (wgpu context + DisplayRenderer), color
(ColorProcessor over ocio-rs), texture, frame, and the commonutil
config helpers.

Fix-ups to make the merged tree build and pass tests:

- oak-core Cargo.toml: wgpu back to 25 (the moved backend code is
  written against that API generation); add the toml/quick-xml/image
  deps oak-common carried.
- lib.rs: drop the duplicate 'pub mod error;'.
- error.rs: unified OAKCORE_* codes; restore Error::new() and
  From<OcioError> from oak-common's error type.
- backend.rs/color.rs: oak_core::/oak_render:: self-references
  rewritten to crate::; the shaderfx-dependent GPU effect test moved
  to oak-render's shaderfx tests (shaderfx depends on oak-node and
  cannot live in oak-core).
- oak-render's error module re-exports oak_core::error::{Error,
  Result}; the OAKRENDER_* codes stay as the public-code contract.
- oak-node jobs.rs: ColorProcessor imported from oak_core::color.
- Integration tests repointed at oak_core::{texture, frame, backend,
  color, colormath}.
- the display-ICC regression test treats an empty OAK_DISPLAY_ICC as
  unset, matching displayicc::env_override_icc.

crates/oak-node/src/nodes/displaytransform.rs

@@ -110,7 +110,7 @@ impl DisplayTransformNode {
 	fn generate_processor(&mut self, core: &mut NodeCore) {
 		let _ = core;
 		// The C++ wraps the color manager, builds a display transform
-		// (`oakcommon_colortransform_init_display`) for the selected
+		// (`oak_core_colortransform_init_display`) for the selected
 		// display/view, resolves the reference color space and creates
 		// the processor via `oakrender_color_processor_create_transform`,
 		// storing it with OcioBase::set_processor. Without a manager (the

crates/oak-node/src/nodes/jobs.rs

@@ -20,11 +20,21 @@
 //! ([`crate::traverser::RenderHooks::resolve`]).
 //! `// CPP-PARITY: app/render/job/footagejob.h, shaderjob.h`.
 
+use oak_core::color::ColorProcessor;
 use oak_core::Rational;
-
 use crate::id::NodeId;
+use crate::nodes::plugin::PluginJobPayload;
 use crate::value::NodeValueRow;
 
+/// Job types
+
+pub enum Job{
+	FootageJob(FootageJobPayload),
+	ShaderJob(ShaderJobPayload),
+	PluginJob(PluginJobPayload),
+	ColorTransformJob
+}
+
 /// C++ `FootageJob` payload: the decode request a footage node emits at
 /// its output instead of a texture. The render hooks decode it at the
 /// request time and replace it with the resulting frame.
@@ -67,6 +77,11 @@ pub struct ShaderJobPayload {
 	pub iterative_input: String,
 }
 
+pub struct ColorTransformJobPayload{
+	pub color_processor: ColorProcessor,
+
+}
+
 impl Default for FootageJobPayload {
 	fn default() -> Self {
 		FootageJobPayload {