multicam: wizard + AFV + node-graph preview + performance

- wizard: angle multi-select, sync modes, auto-align, create sequence;
  keeps the host sequence current (host clip = the multicam clip)
- build_multicam_sequence: per-angle clip -> SOURCES_INPUT[element],
  array slot growth, audio angle tracks for AFV
- AFV: host linked audio clip follows the switched source (one undo),
  muted host audio track disables it
- node-graph preview: inline producer renders through the traverser
  (viewer/project-matched graph frames); sequence viewer uses the graph
- multicam node value(): element-tagged row keys (sources_in[i]),
  reads the current source; build_row keys array inputs by element
- angle grid: viewer=0 (single-track montage, not whole-graph)
- project explorer: rename (dialog) + delete (undoable) real items
- performance: decoded-frame LRU, per-process NVDEC quota (1 session,
  evict before open), GPU composite fail-once fallback, snapshot
  upload debounced on the engine tick, worker vram budget headroom
- timeline clip: multicam overlay via ClipDecorator
- wizard menu item moved to Sequence menu

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

@@ -18,6 +18,7 @@
 //! `src/node/src/input/multicam/multicamnode.{h,cpp}`,
 //! `olive::MultiCamNode`).
 
+use std::any::Any;
 use crate::factory::NodeMeta;
 use crate::id::NodeId;
 use crate::node::{Category, NodeBehavior, NodeCore};
@@ -256,14 +257,12 @@ impl NodeBehavior for MultiCamNode {
 		}
 	}
 
-	/// Evaluate outputs (C++ `value()`): pushes the first value of the
-	/// `sources_in` value array (which, per
-	/// `active_elements_at_time`, is the currently selected source);
-	/// pushes nothing when the array is empty.
-	///
-	/// The Rust row carries no array payload (the `sources_in` value is
-	/// the single active element), so the connected value is pushed
-	/// through as-is; when the input is absent nothing is pushed.
+	/// Evaluate outputs (C++ `value()`): pushes the ARRAY element of
+	/// `sources_in` selected by `current_in` (the current source) — the
+	/// traverser stores array elements under `{input}[{element}]` keys
+	/// ([`crate::traverser`]), so the selected source's texture is the
+	/// value at `sources_in[source]`. A missing element (or an absent
+	/// array) pushes nothing.
 	fn value(
 		&self,
 		core: &NodeCore,
@@ -271,7 +270,19 @@ impl NodeBehavior for MultiCamNode {
 		time: Rational,
 		table: &mut NodeValueTable,
 	) {
-		let _ = (core, time);
+		let _ = time;
+		let source = core.standard_value(CURRENT_INPUT, -1).to_double() as i32;
+		let key = if source >= 0 {
+			format!("{SOURCES_INPUT}[{source}]")
+		} else {
+			SOURCES_INPUT.to_string()
+		};
+		if let Some(v) = inputs.get(&key) {
+			table.push(v.value_type(), v.clone(), None);
+			return;
+		}
+		// Fallback: an unindexed source value (single-source wiring from
+		// before the element-tagged rows).
 		if let Some(v) = inputs.get(SOURCES_INPUT) {
 			table.push(v.value_type(), v.clone(), None);
 		}

crates/oak-node/src/traverser.rs

@@ -254,6 +254,11 @@ fn build_row(
 		// which elements are live at this time (C++
 		// `GetActiveElementsAtTime` — a track pulls only the blocks
 		// covering the frame). An empty answer means "no restriction".
+		// Element-tagged keys: an array input's per-element values coexist
+		// in the row under `{input}[{element}]` (C++ `GetValueAtTime`
+		// indexes the array; the multi-cam node reads exactly the element
+		// of its current source — a plain `id` key would collapse the
+		// array to its last element).
 		if conns.iter().any(|(_, e)| *e >= 0) {
 			let active = entry.behavior.active_elements_at_time(id, time);
 			if !active.is_empty() {
@@ -271,7 +276,12 @@ fn build_row(
 				.get(&(from, upstream_time))
 				.map(|t| pick_value(t, entry.core.input_data_type(id)))
 				.unwrap_or(NodeValue::None);
-			row.insert(id.to_string(), value);
+			let key = if element >= 0 {
+				format!("{id}[{element}]")
+			} else {
+				id.to_string()
+			};
+			row.insert(key, value);
 		}
 	}
 	row