fix(select,multiselect,listbox): enable generic type inference for options and slots

[YevheniiKotyrlo]

Defect Fixes

Fixes #8482

Select, MultiSelect, and Listbox use any for their options prop and all slot scoped data. Developers get no IDE autocomplete and no compile-time safety when working with option slots — the most common interaction pattern for these components.

Same root cause as #8442 — DefineComponent's no-arg constructor prevents generic inference. Same fix pattern as #8444 (DataTable/DatePicker).

Related: #7426, #6041

Reproducer: StackBlitz — run bun run type-check in terminal (0 errors — typo undetected), then bun run patch && bun run type-check (TS2339 — typo caught)

Problem

<Select :options="users" optionLabel="name">
  <template #option="{ option }">
    {{ option.naem }}
    <!-- No error — `option` is `any`, typo ships to production -->
  </template>
</Select>

After this fix, TypeScript infers T = User from the :options binding and propagates it to all slots and callbacks:

<Select :options="users" optionLabel="name">
  <template #option="{ option }">
    {{ option.naem }}
    <!-- TS2339: Property 'naem' does not exist on type 'User' -->
  </template>
</Select>

The template code is identical — only the type inference changes.

Changes

For each component (Select, MultiSelect, Listbox):

• [Component]Props<T = any> — options: T[], callback params (data: T) => ...
• [Component]Slots<T = any> — option: T, options: T[] in header/footer/loader slots
• Generic constructor: new <T = any>(props: [Component]Props<T>) with $slots: [Component]Slots<T>
• modelValue stays any — when optionValue is set, the value is the extracted scalar (e.g., string), not the option object (e.g., User). Typing both as T would cause false positives across every consumer that uses optionValue.

What gets typed

Slot/Callback	Before	After
#option slot option	any	T
#header / #footer slot options	any[]	T[]
#optiongroup slot option	any	T
optionLabel callback param	any	T
optionValue callback param	any	T
optionDisabled callback param	any	T
modelValue	any	any (unchanged — see above)

Scope / Impact

• No breaking changes — backward compatible, T defaults to any
• No runtime changes — types only (.d.ts files)
• 3 components with identical pattern: Select, MultiSelect, Listbox

Verification

Gate	Result
vue-tsc --noEmit with strictTemplates	0 new errors, 1 real bug caught (union of incompatible option arrays in consumer code)
All CI gates (format, lint, test, build)	PASS

Series

This is part of a series bringing generic type inference to all PrimeVue data components:

PR	Components	Status
#8444	DataTable, DatePicker	Open
#8484	Select, MultiSelect, Listbox	This PR
#8485	Column (phantom of prop)	Open
#8489	AutoComplete, CascadeSelect, DataView	Open
#8490	Carousel, Galleria, Timeline	Open
#8491	OrderList, PickList	Open
#8493	VirtualScroller, SelectButton, InputChips	Open

After this series, every PrimeVue component with a collection prop will infer T from the binding and flow it to slots — giving developers full IDE autocomplete and compile-time type safety in templates.