1.1.4: 2-column export + welcome rework with auto-load + archive

- Export dialog goes wide (xl modal) and splits into two columns:
  Project & code on the left (.ruw, runtime.js, animation.js,
  example.html), Media on the right with the per-export size + fps
  inputs followed by MP4 / WebM / GIF / APNG / APNG preview. Skip-
  hidden toggle still spans the full width up top. Single-column
  fallback below 720px.

- Welcome dialog reworked:
  - Always auto-loads the last edited project on boot. The welcome
    dialog opens on top only when the new "Show on start"
    preference is enabled, or unconditionally when there are no
    recents (first-run flow).
  - Two-column body: Recent (max 5 thumbnail tiles, was 8) on the
    left, Archive (compact list view, no thumbnails) on the right.
  - Footer toggle binds to the new useShowWelcomeOnStart shared
    ref so the user can opt out of the boot dialog inline.
- Document settings → Interface tab grows a matching "Show welcome
  screen on start" toggle so users who turned it off can flip it
  back on without diving into localStorage.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/i18n/messages.ts

@@ -58,6 +58,12 @@ export const en = {
       message: '"{name}" will be permanently removed from browser storage.',
       confirm: 'Delete',
     },
+    recentHeading: 'Recent',
+    archiveHeading: 'Archive',
+    noRecents: 'No recent projects yet.',
+    noArchive: 'Older projects appear here once your recents fill up.',
+    showOnStart: 'Show on start',
+    showOnStartHelp: 'Open this dialog when RUWIO launches. Off → app boots straight into the last edited project.',
     backupAll: 'Backup all…',
     backupAllHelp: 'Save every project in browser storage into a single .ruwbak file.',
     backupEmpty: 'No saved projects yet — nothing to back up.',
@@ -382,6 +388,9 @@ export const en = {
     assetThumbsLabel: 'Asset thumbnails',
     assetThumbsDesc:
       'Render small previews in the Assets / Clips / Buttons panels. Turn off for a compact list when working with lots of items.',
+    welcomeOnStartLabel: 'Show welcome screen on start',
+    welcomeOnStartDesc:
+      'Open the welcome / recents dialog when RUWIO launches. Off → boot straight into the last edited project. The last file is always restored either way; the welcome dialog just gives you a chance to switch.',
     bgVideoLabel: 'Video',
     bgVideoNone: 'No background video',
     bgVideoPickFile: 'Pick video file…',
@@ -470,6 +479,8 @@ export const en = {
     ruwTitle: 'RUWIO project (.ruw)',
     ruwBadge: 'Reimportable',
     ruwDesc: 'Zipped bundle — project JSON + every image / audio asset as a separate file. Drop it onto the welcome screen to reopen.',
+    colProject: 'Project & code',
+    colMedia: 'Media',
   },
 
   tests: {