i18n: About page fully internationalized

HTML:
- tagline: data-i18n-html for line break support
- stats labels: about.files instead of palette.mode_files
- built_with, last_delivery, made_with: data-i18n spans

config.js:
- Months array: 12 French months -> t('month.*')
- Jokes array: 10 French jokes -> t('about.joke_*')
- Joke display: removed hardcoded «» wrappers

Locales:
- +34 new keys (months, jokes, about labels)
- 1231 keys in each locale

frontend/locales/en.json

@@ -1207,5 +1207,30 @@
   "graph.ctrl_hover_preview": "Ctrl+hover = full preview",
   "graph.published_badge": "✅ published",
   "graph.click_to_open": "click to open",
-  "graph.ctrl_hover_preview_short": "Ctrl+hover = preview"
+  "graph.ctrl_hover_preview_short": "Ctrl+hover = preview",
+  "about.tagline": "Your Obsidian notes,<br>simply accessible.",
+  "about.files": "Files",
+  "about.made_with": "Made with ☕, 🎧 and a few accidental <code>git push --force</code>.",
+  "month.january": "January",
+  "month.february": "February",
+  "month.march": "March",
+  "month.april": "April",
+  "month.may": "May",
+  "month.june": "June",
+  "month.july": "July",
+  "month.august": "August",
+  "month.september": "September",
+  "month.october": "October",
+  "month.november": "November",
+  "month.december": "December",
+  "about.joke_0": "0 known bugs. The others are shy.",
+  "about.joke_1": "Compiles on the first try. (Except Monday mornings.)",
+  "about.joke_2": "Written by a human. Probably.",
+  "about.joke_3": "No LLMs were harmed during this development.",
+  "about.joke_4": "When it works, we call it a feature.",
+  "about.joke_5": "CSS: 90% of dev time, 10% of the code.",
+  "about.joke_6": "Dark mode active since the project's birth.",
+  "about.joke_7": "Works on my machine™",
+  "about.joke_8": "Technically, everything is an edge case.",
+  "about.joke_9": "The CSS for this panel took longer than the backend."
 }