fix FLOAT widget incrementing broken & disabled state styles on widget number input (Vue) (#6036)

## Summary

Align Vue node number widgets with Figma by centralising button styling
and surfacing disabled-state tokens in the design system.

## Changes

- **What**: Added shared
[`useNumberWidgetButtonPt`](src/renderer/extensions/vueNodes/widgets/composables/useNumberWidgetButtonPt.ts)
helper so both PrimeVue `InputNumber` widgets reuse the same Tailwind
token classes, and added the `color/tokens/alpha` values in
[`packages/design-system/src/css/style.css`](packages/design-system/src/css/style.css#L89-L212)
so semantic aliases remain token-driven ([PrimeVue passthrough
docs](https://www.primefaces.org/primevue/passthrough) w
[`color-mix`](https://www.w3.org/TR/css-color-5/#color-mix))

## Review Focus

Confirm hover/active/disabled colours match the design tokens in both
light and dark themes and that float precision still respects the
safe-range guard.

<img width="1377" height="1150" alt="Screenshot from 2025-10-12
17-53-23"
src="https://github.com/user-attachments/assets/c7d34870-5d07-4ce1-9272-7def7ae813b6"
/>

<img width="1377" height="1150" alt="Screenshot from 2025-10-12
17-53-32"
src="https://github.com/user-attachments/assets/86872ec8-979b-4586-879c-41a126a5f932"
/>

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6036-fix-disabled-state-styles-on-Vue-widget-number-input-INT-and-FLOAT-widgets-28b6d73d365081f8aef7fa860b641f7d)
by [Unito](https://www.unito.io)

---------

Co-authored-by: github-actions <github-actions@github.com>

packages/design-system/src/css/style.css

@@ -89,6 +89,21 @@
   --color-node-hover-100: rgb(from var(--color-charcoal-100) r g b/ 0.15);
   --color-node-hover-200: rgb(from var(--color-charcoal-100) r g b/ 0.1);
   --color-modal-tag: rgb(from var(--color-gray-400) r g b/ 0.4);
+  --color-alpha-charcoal-600-30: color-mix(
+    in srgb,
+    var(--color-charcoal-600) 30%,
+    transparent
+  );
+  --color-alpha-stone-100-20: color-mix(
+    in srgb,
+    var(--color-stone-100) 20%,
+    transparent
+  );
+  --color-alpha-gray-500-50: color-mix(
+    in srgb,
+    var(--color-gray-500) 50%,
+    transparent
+  );
 
   /* PrimeVue pulled colors */
   --color-muted: var(--p-text-muted-color);
@@ -155,6 +170,8 @@
     from var(--color-zinc-500) r g b / 10%
   );
   --node-component-widget-skeleton-surface: var(--color-zinc-300);
+  --node-component-disabled: var(--color-alpha-stone-100-20);
+  --node-icon-disabled: var(--color-alpha-gray-500-50);
   --node-stroke: var(--color-gray-400);
   --node-stroke-selected: var(--color-accent-primary);
   --node-stroke-error: var(--color-error);
@@ -184,6 +201,8 @@
   --node-component-tooltip-border: var(--color-slate-300);
   --node-component-tooltip-surface: var(--color-charcoal-800);
   --node-component-widget-skeleton-surface: var(--color-zinc-800);
+  --node-component-disabled: var(--color-alpha-charcoal-600-30);
+  --node-icon-disabled: var(--color-alpha-stone-100-20);
   --node-stroke: var(--color-stone-200);
   --node-stroke-selected: var(--color-pure-white);
   --node-stroke-error: var(--color-error);
@@ -224,6 +243,8 @@
   --color-node-component-widget-skeleton-surface: var(
     --node-component-widget-skeleton-surface
   );
+  --color-node-component-disabled: var(--node-component-disabled);
+  --color-node-icon-disabled: var(--node-icon-disabled);
   --color-node-stroke: var(--node-stroke);
   --color-node-stroke-selected: var(--node-stroke-selected);
   --color-node-stroke-error: var(--node-stroke-error);