feat(web): lien « Buy me a coffee » (nav, réglages, funding)

- constante BUYMEACOFFEE_URL ; item de nav « Offrez-moi un café »
- section support dans les Réglages + i18n EN/FR
- champ `funding` dans le package.json publié ; mentions README EN/FR

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/web/src/i18n/en.ts

@@ -182,6 +182,7 @@ export default {
     help: 'Help',
     more: 'More',
     gitea: 'Source code',
+    buymeacoffee: 'Buy me a coffee',
     waiting: 'waiting',
   },
   controls: {
@@ -364,6 +365,10 @@ export default {
     vapidContact: 'VAPID contact',
     none: 'none',
     flagHint: 'CLI flag: {flag}',
+    // Support
+    support: 'Support',
+    supportHint: 'Arboretum is a free, self-funded side project. If it saves you time, you can support its development.',
+    supportCta: 'Buy me a coffee',
   },
   help: {
     title: 'Help',