Merge branch 'worktree-agent-a798505697e9a8db3'

# Conflicts:
#	crates/engine/src/commands/mod.rs
#	crates/engine/src/lib.rs
#	crates/ui-egui/src/lib.rs

crates/render/src/cache.rs

@@ -112,6 +112,29 @@ impl LayerCache {
         }
     }
 
+    /// The memory budget in bytes.
+    pub fn budget(&self) -> usize {
+        self.inner.lock().map(|g| g.budget).unwrap_or(0)
+    }
+
+    /// Change the memory budget (evicts least-recently used entries when shrinking).
+    pub fn set_budget(&self, budget: usize) {
+        let Ok(mut g) = self.inner.lock() else { return };
+        g.budget = budget;
+        if g.bytes > budget {
+            let mut by_age: Vec<(u64, u64)> = g.map.iter().map(|(k, e)| (e.last_use, *k)).collect();
+            by_age.sort_unstable();
+            for (_, k) in by_age {
+                if g.bytes <= budget {
+                    break;
+                }
+                if let Some(e) = g.map.remove(&k) {
+                    g.bytes -= e.bytes;
+                }
+            }
+        }
+    }
+
     pub fn clear(&self) {
         if let Ok(mut g) = self.inner.lock() {
             g.map.clear();

crates/render/src/lib.rs

@@ -37,6 +37,13 @@ pub trait FootageSource: Send + Sync {
     fn audio(&self, _item: ItemId, _footage: &Footage, _t: Tick, _frames: usize, _rate: u32) -> Option<Vec<f32>> {
         None
     }
+    /// Set the decoded-frame cache budget in bytes (Settings ▸ Memory & CPU); sources without
+    /// a cache ignore it.
+    fn set_cache_budget(&self, _bytes: usize) {}
+    /// The decoded-frame cache budget in bytes, if the source has a cache.
+    fn cache_budget(&self) -> Option<usize> {
+        None
+    }
 }
 
 /// Layer parameters and audio for effects (see [`effectcraft_effects::EffectHost`]).