Add self-service account deletion

Settings → Delete account removes the signed-in account and everything it
owns. DELETE /api/me re-checks the password (guarding an unattended session),
then wipes the user's events, config, sessions and user row in one transaction
and removes their photos/<user_id>/ directory. The client clears the account's
local cache and returns to the login screen.

Bumps the service-worker cache so clients pick up the new UI.

Verified: wrong password is rejected (401, data intact); correct password
returns 204, invalidates the session, drops all rows to zero and removes the
photo dir; the email can be re-registered afterwards. Confirmed end to end in
a headless-browser run of the Settings → delete flow.

src/app.js

@@ -1522,6 +1522,50 @@
     settingsDialog.close();
   });
 
+  // ---------- delete account ----------
+  const deleteAccountDialog   = document.getElementById("delete-account-dialog");
+  const deleteAccountPassword = document.getElementById("delete-account-password");
+  const deleteAccountError    = document.getElementById("delete-account-error");
+  const deleteAccountConfirm  = document.getElementById("delete-account-confirm");
+
+  document.getElementById("delete-account-btn").addEventListener("click", () => {
+    settingsDialog.close();
+    deleteAccountPassword.value = "";
+    deleteAccountError.hidden = true;
+    deleteAccountDialog.showModal();
+    setTimeout(() => deleteAccountPassword.focus(), 50);
+  });
+
+  deleteAccountConfirm.addEventListener("click", async () => {
+    deleteAccountError.hidden = true;
+    deleteAccountConfirm.disabled = true;
+    try {
+      const res = await fetch("api/me", {
+        method: "DELETE",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ password: deleteAccountPassword.value }),
+      });
+      if (!res.ok) {
+        const msg = (await res.text()).trim();
+        throw new Error(res.status === 401 ? "Incorrect password" : (msg || `HTTP ${res.status}`));
+      }
+      // Account is gone server-side. Wipe this user's local cache before the
+      // reload drops us back on the login screen.
+      try {
+        localStorage.removeItem(eventsKey());
+        localStorage.removeItem(configKey());
+      } catch { /* ignore */ }
+      clearUser();
+      deleteAccountDialog.close();
+      location.reload();
+    } catch (err) {
+      deleteAccountError.textContent = err.message || "Something went wrong";
+      deleteAccountError.hidden = false;
+    } finally {
+      deleteAccountConfirm.disabled = false;
+    }
+  });
+
   // ---------- wiring ----------
   document.querySelectorAll("button.action").forEach(btn => {
     btn.addEventListener("click", () => openNoteDialog(btn.dataset.type));

src/index.html

@@ -192,6 +192,26 @@
           <button value="cancel" class="ghost">Cancel</button>
           <button value="save" id="settings-save">Save</button>
         </menu>
+        <hr class="settings-sep" />
+        <button type="button" id="delete-account-btn" class="danger danger-block">Delete account…</button>
+      </form>
+    </dialog>
+
+    <dialog id="delete-account-dialog">
+      <form method="dialog" id="delete-account-form">
+        <h3>Delete account</h3>
+        <p class="danger-text">
+          This permanently deletes your account and <strong>all its data</strong> —
+          every event, photo and your puppy profile. This can't be undone.
+        </p>
+        <label>Confirm your password
+          <input type="password" id="delete-account-password" autocomplete="current-password" />
+        </label>
+        <p id="delete-account-error" class="auth-error" hidden></p>
+        <menu>
+          <button value="cancel" class="ghost">Cancel</button>
+          <button type="button" id="delete-account-confirm" class="danger">Delete forever</button>
+        </menu>
       </form>
     </dialog>
 

src/style.css

@@ -599,3 +599,18 @@ button.linklike {
   cursor: pointer;
 }
 button.linklike:hover { text-decoration: underline; filter: none; }
+
+/* ---------- delete account ---------- */
+.settings-sep {
+  border: none;
+  border-top: 1px solid var(--border);
+  margin: 18px 0 12px;
+}
+.danger-block { width: 100%; }
+.danger-text {
+  font-size: 0.9rem;
+  color: var(--muted);
+  margin: 0 0 14px;
+  line-height: 1.4;
+}
+.danger-text strong { color: var(--danger); }

src/sw.js

@@ -1,4 +1,4 @@
-const CACHE = "puppy-tracker-v6";
+const CACHE = "puppy-tracker-v7";
 const PHOTO_CACHE = "puppy-tracker-photos-v1";
 const ASSETS = [
   "./",