Manage the KV cache disc usage from preferences and stats

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/app/projects.rs

@@ -132,7 +132,12 @@ impl App {
     pub(super) fn reload_projects(&mut self) {
         if let Some(database) = &mut self.database {
             match database.load_projects() {
-                Ok(projects) => self.projects = projects,
+                Ok(projects) => {
+                    self.projects = projects;
+                    if super::sweep_orphan_checkpoints(&super::kv_cache_path(), &self.projects) {
+                        self.finish_cache_change();
+                    }
+                }
                 Err(error) => self.error = Some(error),
             }
         }
@@ -190,6 +195,36 @@ mod tests {
         assert_eq!(draft_title(&projects, 99), "Session 1");
     }
 
+    #[test]
+    fn sweeping_removes_checkpoints_of_sessions_that_no_longer_exist() {
+        let directory =
+            std::env::temp_dir().join(format!("ds4-server-sweep-{}", std::process::id()));
+        std::fs::create_dir_all(&directory).unwrap();
+        for name in ["1.bin", "2.bin", "notes.bin", "7.bin"] {
+            std::fs::write(directory.join(name), b"payload").unwrap();
+        }
+        let projects = vec![ProjectWithSessions {
+            project: project(1, "First"),
+            sessions: vec![session(1, 1), session(2, 1)],
+        }];
+
+        assert!(super::super::sweep_orphan_checkpoints(
+            &directory, &projects
+        ));
+
+        assert!(directory.join("1.bin").exists());
+        assert!(directory.join("2.bin").exists());
+        // Not a session checkpoint, so not ours to delete.
+        assert!(directory.join("notes.bin").exists());
+        assert!(!directory.join("7.bin").exists());
+        // Nothing left to sweep on the next pass.
+        assert!(!super::super::sweep_orphan_checkpoints(
+            &directory, &projects
+        ));
+
+        std::fs::remove_dir_all(directory).unwrap();
+    }
+
     fn project(id: i32, name: &str) -> Project {
         Project {
             id,