WIP: Batch 1 — backfill tests for store, search, and workflow

- store.rs: 8 tests (roundtrip, persistence, corrupt/empty file handling)
- io/search.rs: 5 tests (matching, nested dirs, gitignore, empty results)
- workflow.rs: 7 new tests (acceptance logic, summarize, can_start, record, refresh)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/store.rs

@@ -80,3 +80,104 @@ impl StoreOps for JsonFileStore {
         fs::write(&self.path, content).map_err(|e| format!("Failed to write store: {e}"))
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+    use tempfile::TempDir;
+
+    fn store_in(dir: &TempDir, name: &str) -> JsonFileStore {
+        let path = dir.path().join(name);
+        JsonFileStore::new(path).expect("store creation should succeed")
+    }
+
+    #[test]
+    fn new_from_missing_file_creates_empty_store() {
+        let dir = TempDir::new().unwrap();
+        let store = store_in(&dir, "missing.json");
+        assert!(store.get("anything").is_none());
+    }
+
+    #[test]
+    fn new_from_empty_file_creates_empty_store() {
+        let dir = TempDir::new().unwrap();
+        let path = dir.path().join("empty.json");
+        fs::write(&path, "").unwrap();
+        let store = JsonFileStore::new(path).expect("should handle empty file");
+        assert!(store.get("anything").is_none());
+    }
+
+    #[test]
+    fn new_from_corrupt_file_returns_error() {
+        let dir = TempDir::new().unwrap();
+        let path = dir.path().join("corrupt.json");
+        fs::write(&path, "not valid json {{{").unwrap();
+        let result = JsonFileStore::new(path);
+        match result {
+            Err(e) => assert!(e.contains("Failed to parse store"), "unexpected error: {e}"),
+            Ok(_) => panic!("expected error for corrupt file"),
+        }
+    }
+
+    #[test]
+    fn get_set_delete_roundtrip() {
+        let dir = TempDir::new().unwrap();
+        let store = store_in(&dir, "data.json");
+
+        assert!(store.get("key").is_none());
+
+        store.set("key", json!("value"));
+        assert_eq!(store.get("key"), Some(json!("value")));
+
+        store.set("key", json!(42));
+        assert_eq!(store.get("key"), Some(json!(42)));
+
+        store.delete("key");
+        assert!(store.get("key").is_none());
+    }
+
+    #[test]
+    fn save_persists_and_reload_restores() {
+        let dir = TempDir::new().unwrap();
+        let path = dir.path().join("persist.json");
+
+        {
+            let store = JsonFileStore::new(path.clone()).unwrap();
+            store.set("name", json!("story-kit"));
+            store.set("version", json!(1));
+            store.save().expect("save should succeed");
+        }
+
+        let store = JsonFileStore::new(path).unwrap();
+        assert_eq!(store.get("name"), Some(json!("story-kit")));
+        assert_eq!(store.get("version"), Some(json!(1)));
+    }
+
+    #[test]
+    fn save_creates_parent_directories() {
+        let dir = TempDir::new().unwrap();
+        let path = dir.path().join("nested").join("deep").join("store.json");
+        let store = JsonFileStore::new(path.clone()).unwrap();
+        store.set("key", json!("value"));
+        store.save().expect("save should create parent dirs");
+        assert!(path.exists());
+    }
+
+    #[test]
+    fn delete_nonexistent_key_is_noop() {
+        let dir = TempDir::new().unwrap();
+        let store = store_in(&dir, "data.json");
+        store.delete("nonexistent");
+        assert!(store.get("nonexistent").is_none());
+    }
+
+    #[test]
+    fn from_path_works_like_new() {
+        let dir = TempDir::new().unwrap();
+        let path = dir.path().join("via_from.json");
+        let store = JsonFileStore::from_path(&path).unwrap();
+        store.set("test", json!(true));
+        assert_eq!(store.get("test"), Some(json!(true)));
+    }
+}