feat: Firebase integration, 3-step new trip form, full country list, and UI polish

- Connect Firestore for journal entries and visited countries (real-time onSnapshot)
- Connect Firebase Storage for photo uploads
- Add NewEntryForm: 3-step flow (trip details → photos → reflection questions)
- Expand country list to full world-atlas dataset (~240 countries) matching the map
- Filter city suggestions by selected country in both NewEntryForm and EditForm
- Redesign StatsPanel as floating horizontal card with donut chart and progress bar
- Center timeline layout with responsive side margins
- Replace "entry" language with "trip" throughout (Add trip, Save trip, Delete trip)
- Remove footer from Layout

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/stores/journalStore.js

@@ -1,4 +1,8 @@
 import { writable } from 'svelte/store';
+import { db } from '../firebase.js';
+import {
+  collection, onSnapshot, addDoc, updateDoc, deleteDoc, doc, serverTimestamp
+} from 'firebase/firestore';
 
 /**
  * @typedef {{
@@ -14,110 +18,28 @@ import { writable } from 'svelte/store';
  * }} JournalEntry
  */
 
-/** @type {JournalEntry[]} */
-const mockEntries = [
-  {
-    id: '1',
-    title: 'First Day in Tokyo',
-    date: '2024-03-15',
-    location: { country: 'Japan', cities: ['Tokyo'] },
-    photos: [
-      'https://images.unsplash.com/photo-1540959733332-eab4deabeeaf?w=600&q=80',
-      'https://images.unsplash.com/photo-1513407030348-c983a97b98d8?w=600&q=80',
-      'https://images.unsplash.com/photo-1490806843957-31f4c9a91c65?w=600&q=80',
-    ],
-    transport: 'flight',
-    tripType: 'solo',
-    days: 5,
-    memo: 'Got completely lost in Shinjuku — stumbled into a tiny ramen shop with no English menu. The chashu just melted. Worth every wrong turn.',
-  },
-  {
-    id: '2',
-    title: 'Arashiyama Bamboo Grove',
-    date: '2024-03-18',
-    location: { country: 'Japan', cities: ['Kyoto'] },
-    photos: [
-      'https://images.unsplash.com/photo-1528360983277-13d401cdc186?w=600&q=80',
-      'https://images.unsplash.com/photo-1545569341-9eb8b30979d9?w=600&q=80',
-    ],
-    transport: 'train',
-    tripType: 'friends',
-    days: 3,
-    memo: 'Arrived at 6am before the crowds. Just me and the wind moving through the bamboo. One of those moments you keep coming back to.',
-  },
-  {
-    id: '3',
-    title: 'Sunset on Montmartre',
-    date: '2024-06-02',
-    location: { country: 'France', cities: ['Paris'] },
-    photos: [
-      'https://images.unsplash.com/photo-1502602898657-3e91760cbb34?w=600&q=80',
-      'https://images.unsplash.com/photo-1499856871958-5b9627545d1a?w=600&q=80',
-      'https://images.unsplash.com/photo-1511739001486-6bfe10ce785f?w=600&q=80',
-    ],
-    transport: 'flight',
-    tripType: 'solo',
-    days: 7,
-    memo: 'Watched the whole city turn orange from the steps of Sacré-Cœur. A street musician was playing La Vie en Rose. Cliché, perfect.',
-  },
-  {
-    id: '4',
-    title: 'Inside La Sagrada Família',
-    date: '2024-06-10',
-    location: { country: 'Spain', cities: ['Barcelona'] },
-    photos: [
-      'https://images.unsplash.com/photo-1523531294919-4bcd7c65e216?w=600&q=80',
-      'https://images.unsplash.com/photo-1583422409516-2895a77efded?w=600&q=80',
-    ],
-    transport: 'flight',
-    tripType: 'friends',
-    days: 4,
-    memo: 'Nothing prepares you for the light inside. The stained glass turns the whole nave into a kaleidoscope. Gaudí was building a forest.',
-  },
-  {
-    id: '5',
-    title: 'Central Park in Fall',
-    date: '2023-10-20',
-    location: { country: 'USA', cities: ['New York'] },
-    photos: [
-      'https://images.unsplash.com/photo-1534430480872-3498386e7856?w=600&q=80',
-      'https://images.unsplash.com/photo-1485871981521-5b1fd3805345?w=600&q=80',
-      'https://images.unsplash.com/photo-1522083165195-3424ed129620?w=600&q=80',
-    ],
-    transport: 'car',
-    tripType: 'friends',
-    days: 6,
-    memo: 'Peak foliage. Joggers, picnics, a guy playing saxophone near Bethesda Fountain. Hard to believe a city this big wraps around this much quiet.',
-  },
-  {
-    id: '6',
-    title: 'Wat Pho Reclining Buddha',
-    date: '2024-01-08',
-    location: { country: 'Thailand', cities: ['Bangkok'] },
-    photos: [
-      'https://images.unsplash.com/photo-1563492065599-3520f775eeed?w=600&q=80',
-      'https://images.unsplash.com/photo-1552465011-b4e21bf6e79a?w=600&q=80',
-    ],
-    transport: 'ship',
-    tripType: 'solo',
-    days: 2,
-    memo: 'Stood in front of the 45m golden Buddha for a long time. The mother-of-pearl inlay on the soles of the feet is impossibly detailed.',
-  },
-];
+export const journals = writable(/** @type {JournalEntry[]} */([]));
+export const journalsLoading = writable(true);
 
-export const journals = writable(mockEntries);
+const entriesRef = collection(db, 'entries');
+
+onSnapshot(entriesRef, (snap) => {
+  journals.set(snap.docs.map(d => ({ id: d.id, ...d.data() })));
+  journalsLoading.set(false);
+});
 
 /** @param {Omit<JournalEntry, 'id'>} entry */
-export function addJournal(entry) {
-  journals.update((entries) => [...entries, { ...entry, id: crypto.randomUUID() }]);
+export async function addJournal(entry) {
+  await addDoc(entriesRef, { ...entry, createdAt: serverTimestamp() });
 }
 
 /** @param {string} id */
-export function removeJournal(id) {
-  journals.update((entries) => entries.filter((e) => e.id !== id));
+export async function removeJournal(id) {
+  await deleteDoc(doc(db, 'entries', id));
 }
 
 /** @param {JournalEntry} updated */
-export function updateJournal(updated) {
-  journals.update((entries) => entries.map((e) => e.id === updated.id ? updated : e));
+export async function updateJournal(updated) {
+  const { id, ...data } = updated;
+  await updateDoc(doc(db, 'entries', id), data);
 }