refactor(locale): move hardcoded UI strings into english locale

Adds optional namespaces (common, errors, commandPalette, headTitle,
notifications, schedule, events, home, reader, routes, badgePreview,
badgeWall) and extends existing ones (settings.*, lists.*, tools.*,
user.*, hololive.*) on the Locale interface. New fields are optional
so japanese.ts can omit them; svelte-i18n's fallbackLocale handles
the runtime miss.

HeadTitle gains an optional routeKey prop for type-safe lookup.
defaultActions becomes a factory so the command palette re-reads
locale on language toggle. The existing JP feedback translation
in routes/settings is preserved via japanese.ts.

Out of scope (kept hardcoded): service-worker.ts, app.html,
Landing*.svelte, tools.ts registry, Easter Event 2025 pages.

1 files changed, 4 insertions, 3 deletions

diff --git a/src/routes/events/+page.svelte b/src/routes/events/+page.svelte
index 88a3da9e..0474852b 100644
--- a/src/routes/events/+page.svelte
+++ b/src/routes/events/+page.svelte
@@ -4,13 +4,14 @@ import Event from "$lib/Events/Event.svelte";
 import Message from "$lib/Loading/Message.svelte";
 
 import root from "$lib/Utility/root";
+import locale from "$stores/locale";
 </script>
 
 {#await fetch(root(`/api/events`))}
-  <Message message="Loading events ..." />
+  <Message message={$locale().events?.loadingEvents} />
 {:then eventsResponse}
   {#await eventsResponse.json()}
-    <Message message="Parsing events ..." />
+    <Message message={$locale().events?.parsingEvents} />
   {:then events}
     {#if events}
       {#each events as rawEvent, i}
@@ -22,6 +23,6 @@ import root from "$lib/Utility/root";
       {/each}
     {/if}
   {:catch}
-    <Message message="" loader="ripple" slot withReload>Error parsing events.</Message>
+    <Message message="" loader="ripple" slot withReload>{$locale().events?.errorParsingEvents}</Message>
   {/await}
 {/await}