Redesign app with new UI kit

Redesign the entire app with a new UI kit. Typography, colors, icons,
avatars, and border radii have all been updated for a more polished,
consistent appearance that matches our other products like
radicle-explorer.

- Replace blockies-based avatars with a new DID-based avatar system
- Move Settings and Create Issue into fullscreen modals
- Change the default theme to follow the system theme
- Remove window decorations on macOS for a cleaner, more native feel
- Update the app icon
- Fix popovers and tooltips

Navigation:

- Rewrite app navigation and layouts
- Add a sidebar that gives you access to all your repos
- Change the startup screen to open directly to the notification inbox
- Add a getting started guide shown to new users on first launch

Settings:

- Add a setting to disable the notification badge
- Add a code font setting

Bug fixes:

- Fix reactions and edits incorrectly targeting the root comment
  instead of the intended reply
- Restrict issue/patch state, labels and assignees to delegates only

index.html

@@ -3,9 +3,17 @@
   <head>
     <script>
       // Avoid flickering on app start.
-      if (localStorage.getItem("theme") === "dark") {
+      const storedTheme = localStorage.getItem("theme");
+      if (storedTheme === "dark" || storedTheme === "light") {
+        document.documentElement.setAttribute("data-theme", storedTheme);
+      } else if (window.matchMedia("(prefers-color-scheme: dark)").matches) {
         document.documentElement.setAttribute("data-theme", "dark");
       }
+      const codefont = localStorage.getItem("codefont");
+      document.documentElement.setAttribute(
+        "data-codefont",
+        codefont === "system" ? "system" : "jetbrains",
+      );
     </script>
     <meta charset="UTF-8" />
     <link rel="icon" href="/radicle.svg" type="image/svg+xml" />
@@ -13,25 +21,19 @@
     <title>Radicle</title>
     <link
       rel="preload"
-      href="/fonts/Inter-Regular.woff2"
+      href="/fonts/Booton-Regular.woff2"
       as="font"
       type="font/woff2"
       crossorigin="anonymous" />
     <link
       rel="preload"
-      href="/fonts/Inter-Medium.woff2"
+      href="/fonts/Booton-Medium.woff2"
       as="font"
       type="font/woff2"
       crossorigin="anonymous" />
     <link
       rel="preload"
-      href="/fonts/Inter-SemiBold.woff2"
-      as="font"
-      type="font/woff2"
-      crossorigin="anonymous" />
-    <link
-      rel="preload"
-      href="/fonts/Inter-Bold.woff2"
+      href="/fonts/Booton-SemiBold.woff2"
       as="font"
       type="font/woff2"
       crossorigin="anonymous" />