fix: polish explorer, error states and page alignment

- Explorer: 13px code, page-coloured dark editor, padded Markdown with a
  readable width, full repository ID on hover, sidebar footer kept clear
  of the floating Ko-fi button.
- Explorer errors render as a card with links home and to the FAQ; the
  empty action bar and Raw/Download buttons are hidden.
- Unknown error codes show the generic message instead of the raw
  ERRORS.<code> key.
- All app pages share one content column; New anonymization starts at
  the top instead of floating mid-screen.
- Status page: spaced action buttons, aligned status pill, no second
  Ko-fi embed under the support cards.
- Claim placeholders; consistent notebook option on new conferences.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

public/script/app.js

@@ -201,11 +201,13 @@ export const profileController = function (state, http, translate, timeout, quot
           (error) => {
             state.saving = false;
             const code = error && error.data && error.data.error;
-            const key = "ERRORS." + code;
-            translate(key).then((translation) => {
-              state.error = translation && translation !== key ? translation : "Unable to save your defaults. Please try again.";
+            const fallback = "Unable to save your defaults. Please try again.";
+            // Unknown codes translate to the generic unknown_error message;
+            // this page has a more specific one.
+            Promise.all([translate("ERRORS." + code), translate("ERRORS.unknown_error")]).then(([translation, unknown]) => {
+              state.error = code && translation !== unknown ? translation : fallback;
             }, () => {
-              state.error = "Unable to save your defaults. Please try again.";
+              state.error = fallback;
             });
           }
         );
@@ -2629,7 +2631,7 @@ export const exploreController = function (state, http, location, params, html,
           theme: "chrome",
           useSoftTab: true,
           tabSize: 2,
-          fontSize: 15,
+          fontSize: 13,
           keyBinding: "vscode",
           fullLineSelection: true,
           highlightActiveLine: false,