✨ refactor: pricing filters for dynamic counting & cleaner logic

This commit introduces a unified, maintainable solution for all model-pricing filter buttons and removes redundant code.

Key points
• Added `usePricingFilterCounts` hook
  - Centralises filtering logic and returns:
    - `quotaTypeModels`, `endpointTypeModels`, `dynamicCategoryCounts`, `groupCountModels`
  - Keeps internal helpers private (removed public `modelsAfterCategory`).

• Updated components to consume the new hook
  - `PricingSidebar.jsx`
  - `FilterModalContent.jsx`

• Improved button UI/UX
  - `SelectableButtonGroup.jsx` now respects `item.disabled` and auto-disables when `tagCount === 0`.
  - `PricingGroups.jsx` counts models per group (after all other filters) and disables groups with zero matches.
  - `PricingEndpointTypes.jsx` enumerates all endpoint types, computes filtered counts, and disables entries with zero matches.

• Removed obsolete / duplicate calculations and comments to keep components lean.

The result is consistent, real-time tag counts across all filter groups, automatic disabling of unavailable options, and a single source of truth for filter computations, making future extensions straightforward.

web/src/components/common/ui/SelectableButtonGroup.jsx

@@ -133,6 +133,7 @@ const SelectableButtonGroup = ({
   const contentElement = showSkeleton ? renderSkeletonButtons() : (
     <Row gutter={[8, 8]} style={{ lineHeight: '32px', ...style }} ref={contentRef}>
       {items.map((item) => {
+        const isDisabled = item.disabled || (typeof item.tagCount === 'number' && item.tagCount === 0);
         const isActive = Array.isArray(activeValue)
           ? activeValue.includes(item.value)
           : activeValue === item.value;
@@ -150,10 +151,12 @@ const SelectableButtonGroup = ({
                 onClick={() => { /* disabled */ }}
                 theme={isActive ? 'light' : 'outline'}
                 type={isActive ? 'primary' : 'tertiary'}
+                disabled={isDisabled}
                 icon={
                   <Checkbox
                     checked={isActive}
                     onChange={() => onChange(item.value)}
+                    disabled={isDisabled}
                     style={{ pointerEvents: 'auto' }}
                   />
                 }
@@ -190,6 +193,7 @@ const SelectableButtonGroup = ({
               theme={isActive ? 'light' : 'outline'}
               type={isActive ? 'primary' : 'tertiary'}
               icon={item.icon}
+              disabled={isDisabled}
               style={{ width: '100%' }}
             >
               <span style={{ marginRight: item.tagCount !== undefined ? 4 : 0 }}>{item.label}</span>