Disk cache: drop segmentations and frames made before strokes applied in order (#1646)

Segmentations and rendered frames are keyed by their strokes, which now
segment differently where strokes overlap; bumping both versions keeps old
entries from showing the old result. Frozen mattes are stored in the project
and are untouched.

crates/render/src/disk_cache.rs

@@ -652,7 +652,7 @@ pub fn read_layer_entry(data: &[u8]) -> Option<Buf> {
 /// The disk key of a segmentation: its chain key and scale.
 fn seg_key(key: u64, scale: f64) -> u128 {
     let mut h = Hash128::default();
-    h.write(b"segmentation-v1");
+    h.write(b"segmentation-v2");
     h.write_u64(key);
     h.write_u64(scale.to_bits());
     h.finish()
@@ -772,7 +772,7 @@ fn decode_layer(p: &[u8]) -> Option<Buf> {
 // ---------------------------------------------------------------- content keys
 
 /// Bump when rendering changes in a way that makes old disk entries wrong.
-const RENDER_VERSION: &str = "effectcraft-render-2";
+const RENDER_VERSION: &str = "effectcraft-render-3";
 
 fn hash_debug(h: &mut Hash128, v: &impl std::fmt::Debug) {
     h.write(format!("{v:?}").as_bytes());