🐛 Clamp gradient stop offsets to valid range (#10881)

* 🐛 Clamp gradient stop offsets to valid [0, 1] range

Fixed a bug where gradient stop offsets outside the valid [0, 1] range were being sent to the server, causing schema validation errors ('invalid shape found').

Changes:
- Viewport gradient handler: clamp offset in points-on-pointer-down before creating new stops
- Colorpicker gradient preview: clamp offset in handle-preview-down before adding stops
- Data layer: clamp offset parameter in update-colorpicker-add-stop and all stop offsets in update-colorpicker-stops; added app.common.math require

All clamping follows the existing pattern used in handle-marker-pointer-move.

AI-assisted-by: deepseek-v4-flash

* 💄 Fix formatting in gradient handlers

Fix cljfmt formatting issues in gradient handler functions.

AI-assisted-by: qwen3.7-plus

frontend/src/app/main/data/workspace/colors.cljs

@@ -9,6 +9,7 @@
    [app.common.data :as d]
    [app.common.data.macros :as dm]
    [app.common.files.helpers :as cfh]
+   [app.common.math :as mth]
    [app.common.schema :as sm]
    [app.common.types.color :as clr]
    [app.common.types.fills :as types.fills]
@@ -950,7 +951,8 @@
                       (or (not cap-stops?) (< (count stops) types.fills/MAX-GRADIENT-STOPS))]
 
                   (if can-add-stop?
-                    (let [new-stop (-> (clr/interpolate-gradient stops offset)
+                    (let [offset (mth/clamp offset 0 1)
+                          new-stop (-> (clr/interpolate-gradient stops offset)
                                        (split-color-components))
                           stops (conj stops new-stop)
                           stops (into [] (sort-by :offset stops))
@@ -973,7 +975,8 @@
                       stops (mapv split-color-components
                                   (if cap-stops?
                                     (take types.fills/MAX-GRADIENT-STOPS stops)
-                                    stops))]
+                                    stops))
+                      stops (mapv #(update % :offset (fn [o] (mth/clamp o 0 1))) stops)]
                   (-> state
                       (assoc :current-color (get stops stop))
                       (assoc :stops stops))))))))

frontend/src/app/main/store.cljs

@@ -121,7 +121,7 @@
                    delta      (if prev-t
                                 (str "(+" (ct/diff-ms prev-t t) "ms)")
                                 "(+0ms)")
-                    delta-pad  (str/pad delta {:length 10 :type :right})]
+                   delta-pad  (str/pad delta {:length 10 :type :right})]
                (recur t
                       (next xs)
                       (conj! out (str iso "  " delta-pad "  " name))))

frontend/src/app/main/ui/workspace/colorpicker/gradients.cljs

@@ -233,6 +233,7 @@
          (mf/deps on-add-stop-preview)
          (fn [^js e]
            (let [offset (-> (event->offset e)
+                            (mth/clamp 0 1)
                             (mth/precision 2))]
              (when on-add-stop-preview
                (on-add-stop-preview offset)))))

frontend/src/app/main/ui/workspace/viewport/gradients.cljs

@@ -189,6 +189,7 @@
                    lv (-> (gpt/to-vec from-p to-p) (gpt/unit))
                    nv (gpt/normal-left lv)
                    offset (-> (gsp/project-t position [from-p to-p] nv)
+                              (mth/clamp 0 1)
                               (mth/precision 2))
                    new-stop (cc/interpolate-gradient stops offset)
                    stops (conj stops new-stop)