feat: add Filament admin panel with migrations and design spec

- Add AdminPanelProvider mounting panel at `/admin` with `is_admin` auth guard
- Add `is_admin` boolean column to users table
- Add brent_prices and price_predictions tables with appropriate indexes
- Add comprehensive admin design spec covering resources, dashboard, navigation, and build order
- Configure default panel with amber primary color and standard middleware stack
- Add compiled Filament assets (actions.js, app.css)

public/js/filament/forms/components/checkbox-list.js

@@ -0,0 +1 @@
+function c({livewireId:s}){return{areAllCheckboxesChecked:!1,checkboxListOptions:[],search:"",unsubscribeLivewireHook:null,visibleCheckboxListOptions:[],init(){this.checkboxListOptions=Array.from(this.$root.querySelectorAll(".fi-fo-checkbox-list-option")),this.updateVisibleCheckboxListOptions(),this.$nextTick(()=>{this.checkIfAllCheckboxesAreChecked()}),this.unsubscribeLivewireHook=Livewire.interceptMessage(({message:e,onSuccess:t})=>{t(()=>{this.$nextTick(()=>{e.component.id===s&&(this.checkboxListOptions=Array.from(this.$root.querySelectorAll(".fi-fo-checkbox-list-option")),this.updateVisibleCheckboxListOptions(),this.checkIfAllCheckboxesAreChecked())})})}),this.$watch("search",()=>{this.updateVisibleCheckboxListOptions(),this.checkIfAllCheckboxesAreChecked()})},checkIfAllCheckboxesAreChecked(){this.areAllCheckboxesChecked=this.visibleCheckboxListOptions.length===this.visibleCheckboxListOptions.filter(e=>e.querySelector("input[type=checkbox]:checked, input[type=checkbox]:disabled")).length},toggleAllCheckboxes(){this.checkIfAllCheckboxesAreChecked();let e=!this.areAllCheckboxesChecked;this.visibleCheckboxListOptions.forEach(t=>{let i=t.querySelector("input[type=checkbox]");i.disabled||i.checked!==e&&(i.checked=e,i.dispatchEvent(new Event("change")))}),this.areAllCheckboxesChecked=e},updateVisibleCheckboxListOptions(){this.visibleCheckboxListOptions=this.checkboxListOptions.filter(e=>["",null,void 0].includes(this.search)||e.querySelector(".fi-fo-checkbox-list-option-label")?.innerText.toLowerCase().includes(this.search.toLowerCase())?!0:e.querySelector(".fi-fo-checkbox-list-option-description")?.innerText.toLowerCase().includes(this.search.toLowerCase()))},destroy(){this.unsubscribeLivewireHook?.()}}}export{c as default};