Fix annotations not persisting across reload (keyword round-trip)

Keyword *values* don't survive JSON: clj->js stringifies :annotation/:root/clip
refs and js->clj only re-keywordizes keys, so a reloaded annotation had string
:type/:parent/:ref and was filtered out of the scene. Re-keywordize those fields
on load (scene/restore-annotations) and give marks string ids (random-uuid was
serializing as a UUID object).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tl/src/tl/events.cljs

@@ -47,7 +47,7 @@
  (fn [db [_ detail otio-raw scene-resp]]
    (let [parsed (otio/parse otio-raw)
          base   (scene/from-otio parsed)
-         anns   (get-in scene-resp [:scene :groups] {})]  ; saved annotation layer
+         anns   (scene/restore-annotations (get-in scene-resp [:scene :groups] {}))]
      (-> db
          (assoc :project detail :page :editor)
          (assoc :fps (or (:fps scene-resp) (:fps parsed)))

tl/src/tl/scene.cljs

@@ -177,7 +177,7 @@
   (mapv (fn [{:keys [mark src]}]
           (let [{:keys [xs]} (target-range scene mark)
                 [a b] src]
-            {:id (random-uuid)
+            {:id (str (random-uuid))                ; string so it survives JSON
              :start {:ref mark :at (- a xs)}
              :end   {:ref mark :at (- b xs)}}))
         (slice (content-segments scene ctx) la lb)))
@@ -219,6 +219,24 @@
     (let [{:keys [xs xe]} (target-range scene ref)] (+ (- xe xs) at 1))
     at))
 
+(defn- restore-mark [m]
+  (cond-> m
+    (get-in m [:start :ref]) (update-in [:start :ref] keyword)
+    (get-in m [:end :ref])   (update-in [:end :ref] keyword)
+    (:track m)               (update :track keyword)))
+
+(defn restore-annotations
+  "Re-keywordize the fields that lose their keyword-ness through JSON: a saved
+   annotation round-trips with string :type/:parent and string mark :refs, so
+   put them back before merging into the (keyword-keyed) scene."
+  [anns]
+  (into {} (map (fn [[gid g]]
+                  [gid (-> g
+                           (update :type keyword)
+                           (update :parent keyword)
+                           (update :marks #(mapv restore-mark (or % []))))]))
+        anns))
+
 (defn marks->rows
   "Render single-clip `marks` as editor rows (one {:s … :e …} per mark, frames
    normalised to mark time). 1:1 with `marks`, so row i pairs with mark i."

tl/test/tl/scene_test.cljs

@@ -221,6 +221,18 @@
         (is (= 0  (get-in (first marks) [:start :at])))
         (is (= 30 (get-in (first marks) [:end :at])))))))
 
+(deftest restore-annotations-rekeywordizes-json
+  (testing "a JSON-roundtripped annotation (string :type/:parent/:ref) is restored + resolves"
+    (let [json-like {:ann-1 {:type "annotation" :parent "root" :name "x"
+                             :marks [{:id "m1" :start {:ref "clip-a" :at 0}
+                                              :end   {:ref "clip-a" :at -1}}]}}
+          g (:ann-1 (s/restore-annotations json-like))]
+      (is (= :annotation (:type g)))
+      (is (= :root (:parent g)))
+      (is (= :clip-a (get-in g [:marks 0 :start :ref])))
+      (let [scene (assoc-in base [:groups :ann-1] g)]
+        (is (= [0 100] (:src (first (s/resolve scene :ann-1)))))))))
+
 (deftest marks-to-rows-normalises-frames
   (testing "marks->rows is 1:1 with marks and normalises :at -1 to the length"
     (let [rows (s/marks->rows base [{:id :m :start {:ref :clip-a :at 0}