refactor: delete-wallet-confirm as standalone full view

Replace the inline confirmation div at the bottom of Settings with a
proper full-screen view (view-delete-wallet-confirm). This fixes the
issue where the confirmation was offscreen on the 360x600 popup.

- New view with back button, title, warning text, password input,
  and red-text Confirm Delete button
- Dedicated flash area for password errors
- New deleteWallet.js module with init/show pattern
- Added delete-wallet-confirm to VIEWS array in helpers.js
- Removed old inline confirmation HTML and logic from settings

src/popup/index.html

@@ -841,39 +841,41 @@
                     </p>
                     <div id="settings-denied-sites"></div>
                 </div>
+            </div>
 
-                <div
-                    id="delete-wallet-confirm"
-                    class="hidden border border-border border-dashed p-3 mt-2 mb-3"
+            <!-- ============ DELETE WALLET CONFIRM ============ -->
+            <div id="view-delete-wallet-confirm" class="view hidden">
+                <button
+                    id="btn-delete-wallet-back"
+                    class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer mb-2"
                 >
-                    <h3 class="font-bold mb-1">Confirm Deletion</h3>
-                    <p class="text-xs text-muted mb-2">
-                        Delete <strong id="delete-wallet-name"></strong>? This
-                        is permanent. Any funds will be unrecoverable without
-                        your recovery phrase.
-                    </p>
-                    <p class="text-xs mb-2">Enter your password to confirm:</p>
+                    &lt; Back
+                </button>
+                <h2 class="font-bold mb-3">Delete Wallet</h2>
+                <p class="text-xs mb-3">
+                    Deleting
+                    <strong id="delete-wallet-name"></strong> is permanent. Any
+                    funds will be unrecoverable without your recovery phrase.
+                </p>
+                <div
+                    id="delete-wallet-flash"
+                    class="text-xs text-red-500 mb-2 hidden"
+                ></div>
+                <div class="mb-2">
+                    <label class="block mb-1">Password</label>
                     <input
                         type="password"
                         id="delete-wallet-password"
-                        class="border border-border p-1 w-full text-sm bg-bg text-fg mb-2"
-                        placeholder="Password"
+                        class="border border-border p-1 w-full font-mono text-sm bg-bg text-fg"
+                        placeholder="Enter your password to confirm"
                     />
-                    <div class="flex gap-2">
-                        <button
-                            id="btn-delete-wallet-confirm"
-                            class="border border-border text-fg px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
-                        >
-                            Delete
-                        </button>
-                        <button
-                            id="btn-delete-wallet-cancel"
-                            class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
-                        >
-                            Cancel
-                        </button>
-                    </div>
                 </div>
+                <button
+                    id="btn-delete-wallet-confirm"
+                    class="border border-border text-red-500 px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
+                >
+                    Confirm Delete
+                </button>
             </div>
 
             <!-- ============ SETTINGS: ADD TOKEN ============ -->