feat: migrate icons to SF Symbols, refactor explore tab, add collections/programs data layer

- Replace all Ionicons with native SF Symbols via expo-symbols SymbolView
- Create reusable Icon wrapper component (src/shared/components/Icon.tsx)
- Remove @expo/vector-icons and lucide-react dependencies
- Refactor explore tab with filters, search, and category browsing
- Add collections and programs data with Supabase integration
- Add explore filter store and filter sheet
- Update i18n strings (en, de, es, fr) for new explore features
- Update test mocks and remove stale snapshots
- Add user fitness level to user store and types

supabase/seed.ts

@@ -12,9 +12,59 @@
 import { createClient } from '@supabase/supabase-js'
 import { WORKOUTS } from '../src/shared/data/workouts'
 import { TRAINERS } from '../src/shared/data/trainers'
-import { COLLECTIONS, PROGRAMS } from '../src/shared/data/collections'
+import { PROGRAMS } from '../src/shared/data/programs'
 import { ACHIEVEMENTS } from '../src/shared/data/achievements'
 
+/**
+ * Seed data for collections — used only for initial database seeding.
+ * The app fetches collections from Supabase at runtime.
+ */
+const SEED_COLLECTIONS = [
+  {
+    id: 'morning-energizer',
+    title: 'Morning Energizer',
+    description: 'Start your day right',
+    icon: '🌅',
+    workoutIds: ['4', '6', '43', '47', '10'],
+  },
+  {
+    id: 'no-equipment',
+    title: 'No Equipment',
+    description: 'Workout anywhere',
+    icon: '💪',
+    workoutIds: ['1', '4', '6', '11', '13', '16', '17', '19', '23', '26', '31', '38', '42', '43', '45'],
+  },
+  {
+    id: '7-day-burn',
+    title: '7-Day Burn Challenge',
+    description: 'Transform in one week',
+    icon: '🔥',
+    workoutIds: ['1', '11', '31', '42', '6', '17', '23'],
+    gradient: ['#FF6B35', '#FF3B30'],
+  },
+  {
+    id: 'quick-intense',
+    title: 'Quick & Intense',
+    description: 'Max effort in 4 minutes',
+    icon: '⚡',
+    workoutIds: ['1', '11', '23', '35', '38', '42', '6', '17'],
+  },
+  {
+    id: 'core-focus',
+    title: 'Core Focus',
+    description: 'Build a solid foundation',
+    icon: '🎯',
+    workoutIds: ['11', '12', '13', '14', '16', '17'],
+  },
+  {
+    id: 'leg-day',
+    title: 'Leg Day',
+    description: 'Never skip leg day',
+    icon: '🦵',
+    workoutIds: ['31', '32', '33', '34', '35', '36', '37'],
+  },
+]
+
 const supabaseUrl = process.env.EXPO_PUBLIC_SUPABASE_URL
 const supabaseKey = process.env.EXPO_PUBLIC_SUPABASE_ANON_KEY
 
@@ -73,7 +123,7 @@ async function seedWorkouts() {
 async function seedCollections() {
   console.log('Seeding collections...')
   
-  const collections = COLLECTIONS.map(c => ({
+  const collections = SEED_COLLECTIONS.map(c => ({
     id: c.id,
     title: c.title,
     description: c.description,
@@ -85,7 +135,7 @@ async function seedCollections() {
   if (error) throw error
 
   // Seed collection-workout relationships
-  const collectionWorkouts = COLLECTIONS.flatMap(c => 
+  const collectionWorkouts = SEED_COLLECTIONS.flatMap(c => 
     c.workoutIds.map((workoutId, index) => ({
       collection_id: c.id,
       workout_id: workoutId,
@@ -102,7 +152,7 @@ async function seedCollections() {
 async function seedPrograms() {
   console.log('Seeding programs...')
   
-  const programs = PROGRAMS.map(p => ({
+  const programs = Object.values(PROGRAMS).map(p => ({
     id: p.id,
     title: p.title,
     description: p.description,
@@ -117,7 +167,7 @@ async function seedPrograms() {
   // Seed program-workout relationships
   let programWorkouts: { program_id: string; workout_id: string; week_number: number; day_number: number }[] = []
   
-  PROGRAMS.forEach(program => {
+  Object.values(PROGRAMS).forEach(program => {
     let week = 1
     let day = 1
     program.workoutIds.forEach((workoutId, index) => {