refactor(task,render): RenderTask family over a new oakrender ticket C ABI

- oakrender: new ticket family (render_frame/render_audio with finished
  callback, result frame/samples access, cancel/wait), project copier
  C API, cache get_invalidated_ranges, manager set_aggressive_gc
- oaknode: node_copy_inputs, set_value_hint_track, viewer params
  setters, video frame cache borrowed outlet, project copy_settings
- oakcodec: encoder desired pixel format, export format extension,
  encoding generate_matrix, custom range in encoding params POD
- oaktask: RenderTask orchestrates oakrender tickets (no Qt threads/
  watchers), PreCacheTask and ExportTask rewritten over the oaknode/
  oakrender/oakcodec C ABIs; frames cross from oakrender to oakcodec
  handles by pixel copy (different control blocks)
- the two-step texture/download render path collapses into single-step
  (tickets always yield frames); subtitle sidecar kept
- tests: 105 in build-oaktask (export/precache factory paths,
  construction, conform end-to-end); regressions all green

include/node/node.h

@@ -23,6 +23,7 @@
 
 #include <stdint.h>
 
+#include "common/videoparams.h"
 #include "node/error.h"
 #include "undo/undocommand.h"
 
@@ -110,6 +111,16 @@ typedef struct OakNodeProject OakNodeProject;
 typedef struct OakNodeMarkerList OakNodeMarkerList;
 typedef struct OakNodeWorkArea OakNodeWorkArea;
 
+/**
+ * @brief Opaque borrowed handle to a node's video frame cache
+ * (olive::FrameHashCache in oakrender). oakrender reinterprets this into
+ * its own handle types.
+ */
+typedef struct OakNodeFrameCache OakNodeFrameCache;
+
+/* oakcore handles used by the viewer setters. */
+typedef struct OakAudioParams OakAudioParams;
+
 /**
  * @brief Number of live owned objects created through this API
  * (nodes from oaknode_factory_create_from_id()/oaknode_node_create_copy(),
@@ -543,6 +554,40 @@ int oaknode_node_get_markers(const OakNodeNode *node,
 int oaknode_node_get_work_area(const OakNodeNode *node,
 							   OakNodeWorkArea **out);
 
+/**
+ * @brief Borrowed video frame cache of a node (NULL when the node has
+ *        none or for NULL input).
+ */
+int oaknode_node_get_video_frame_cache(const OakNodeNode *node,
+									   OakNodeFrameCache **out);
+
+/**
+ * @brief Copy input values/connections from one node to another
+ *        (Node::copy_inputs()). include_connections != 0 also copies
+ *        input connections.
+ */
+int oaknode_node_copy_inputs(OakNodeNode *dst, const OakNodeNode *src,
+							 int include_connections);
+
+/**
+ * @brief Set a track-routing value hint on an input
+ *        (Node::set_value_hint_for_input() with a single texture type
+ *        and a Track::Reference string).
+ */
+int oaknode_node_set_value_hint_track(OakNodeNode *node,
+									  const char *input_id,
+									  int track_type, int track_index);
+
+/**
+ * @brief Set a viewer node's video/audio params (ViewerOutput::
+ * set_video_params/set_audio_params, stream index 0). `params` is an
+ * oakcommon handle (video) or borrowed oakcore handle (audio).
+ */
+int oaknode_viewer_set_video_params(OakNodeNode *viewer,
+									const OakVideoParams *params);
+int oaknode_viewer_set_audio_params(OakNodeNode *viewer,
+									const OakAudioParams *params);
+
 /**
  * @brief Create a command that removes a node from its graph together
  * with its exclusive dependencies and disconnects its edges