Make "Not Logged In" button open Account modal & fix Account loading state ✨ (#3247)

## Description:

**TerritoryPatternsModal.ts**
- Changed the "Not Logged In" indicator from a static `div` to a
clickable `button`
- Clicking it now closes the skins modal and navigates to the Account
page via `window.showPage("page-account")`
- Added hover effect (`hover:bg-red-500/30`) for visual feedback

**AccountModal.ts**
- Fixed the inline Account modal's loading state ("Fetching account
information...") rendering without a background or header (white text on
light background 💀)
- The loading spinner is now wrapped in `modalContainerClass` (dark
glassmorphic background) with a proper `modalHeader` including the title
and back button, matching the loaded state's appearance

**SinglePlayerModal.ts**
- Changed the "Sign in for achievements" banner from a static `div` to a
clickable `button` that closes the modal and navigates to the Account
page
- Added hover effect for visual feedback

**Matchmaking.ts**
- When the "You must be logged in to play ranked matchmaking" toast
appears, the user is now also navigated to the Account page so they can
log in immediately

## Please complete the following:

- [X] I have added screenshots for all UI updates
- [X] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [X] I have added relevant tests to the test directory
- [X] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

FloPinguin

src/client/TerritoryPatternsModal.ts

@@ -220,11 +220,15 @@ export class TerritoryPatternsModal extends BaseModal {
   }
 
   private renderNotLoggedInWarning(): TemplateResult {
-    return html`<div
-      class="px-4 py-2 text-xs font-bold uppercase tracking-wider transition-colors duration-200 rounded-lg bg-red-500/20 text-red-400 border border-red-500/30"
+    return html`<button
+      class="px-4 py-2 text-xs font-bold uppercase tracking-wider transition-colors duration-200 rounded-lg bg-red-500/20 text-red-400 border border-red-500/30 cursor-pointer hover:bg-red-500/30"
+      @click=${() => {
+        this.close();
+        window.showPage?.("page-account");
+      }}
     >
       ${translateText("territory_patterns.not_logged_in")}
-    </div>`;
+    </button>`;
   }
 
   private renderColorSwatchGrid(): TemplateResult {