Remove every automatic timezone-setting mechanism (task 7f685179)

The application timezone is now only ever set by an admin saving it:

- API: drop adopt_reported_timezone; the panel household clock reads the
  stored settings only and ignores any timezone request header.
- Integration: stop reporting Home Assistant's time_zone in an
  X-NestQuest-Timezone header (snapshot, completion and SSE requests).
- Admin app: remove the browser-zone detection and the automatic PATCH
  on load; the timezone field stays a manual control.
- Remove the timezone_configured marker from the core settings, the
  settings store and the admin settings API. A stored document that
  still carries the key loads harmlessly (unknown keys are ignored).

Tests replace the adoption expectations with proofs that a panel
timezone header never changes the stored settings, a fresh install's
empty zone stays empty with no settings write, the admin settings carry
no timezone_configured, and a manual admin timezone PATCH persists.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

admin/src/api/settings.ts

@@ -19,12 +19,6 @@ export interface HouseholdSettings {
   celebration_enabled: boolean;
   /** IANA zone name (e.g. "America/New_York"); "" means the API host's local time. */
   timezone: string;
-  /**
-   * True once the admin explicitly chose `timezone` (even ""); false on a
-   * fresh install, where the screen auto-sets the browser's zone. API-only:
-   * never shown in the form.
-   */
-  timezone_configured: boolean;
 }
 
 /** Only the supplied fields are updated; the API answers with all of them. */

admin/src/settings/SettingsScreen.test.tsx

@@ -23,7 +23,6 @@ const DEFAULT_SETTINGS: HouseholdSettings = {
   end_of_day_report_enabled: true,
   celebration_enabled: false,
   timezone: "America/Chicago",
-  timezone_configured: true,
 };
 
 function child(
@@ -508,7 +507,7 @@ describe("SettingsScreen — preferences", () => {
     save(form);
     await screen.findByText("Preferences saved.");
     expect(writes()).toEqual([
-      { method: "PATCH", path: SETTINGS_PATH, body: { timezone: "Europe/London", timezone_configured: true } },
+      { method: "PATCH", path: SETTINGS_PATH, body: { timezone: "Europe/London" } },
     ]);
     const reloaded = screen.getByRole("form", { name: "Preferences" });
     expect(field(reloaded, "Timezone").value).toBe("Europe/London");
@@ -559,7 +558,7 @@ describe("SettingsScreen — preferences", () => {
   });
 });
 
-describe("SettingsScreen — timezone auto-set", () => {
+describe("SettingsScreen — no timezone auto-set", () => {
   let zoneSpy: ReturnType<typeof vi.spyOn> | null;
 
   function mockBrowserZone(timeZone: string | undefined) {
@@ -575,8 +574,8 @@ describe("SettingsScreen — timezone auto-set", () => {
     sessionStorage.clear();
     storeTokens({ access_token: "at-123", expires_in: 600 });
     children = [child(1, "Declan", 1)];
-    // A fresh install: no zone, and the admin never chose one.
-    settings = { ...DEFAULT_SETTINGS, timezone: "", timezone_configured: false };
+    // A fresh install: no zone stored.
+    settings = { ...DEFAULT_SETTINGS, timezone: "" };
     writeResponse = null;
     zoneSpy = null;
     fetchMock = vi.fn(async (url: string, init?: RequestInit) => routeFetch(url, init));
@@ -595,25 +594,15 @@ describe("SettingsScreen — timezone auto-set", () => {
     return screen.findByRole("form", { name: "Preferences" });
   }
 
-  it("an unset timezone is set once, on load, to the browser's zone and shown", async () => {
+  it("an empty timezone stays empty on load and nothing is written", async () => {
     mockBrowserZone("America/New_York");
     const form = await renderForm();
-    expect(field(form, "Timezone").value).toBe("America/New_York");
-    expect(writes()).toEqual([
-      { method: "PATCH", path: SETTINGS_PATH, body: { timezone: "America/New_York", timezone_configured: true } },
-    ]);
-    expect(settings.timezone).toBe("America/New_York");
-    expect(settings.timezone_configured).toBe(true);
-
-    // A later save of another field does not re-send the timezone.
-    fireEvent.change(field(form, "Planning horizon (days)"), { target: { value: "21" } });
-    fireEvent.click(within(form).getByRole("button", { name: "Save preferences" }));
-    await screen.findByText("Preferences saved.");
-    expect(writes()).toHaveLength(2);
-    expect(writes()[1].body).toEqual({ horizon_days: 21 });
+    expect(field(form, "Timezone").value).toBe("");
+    expect(writes()).toEqual([]);
+    expect(settings.timezone).toBe("");
   });
 
-  it("StrictMode's doubled effects still auto-set exactly once", async () => {
+  it("StrictMode's doubled effects write nothing either", async () => {
     mockBrowserZone("America/New_York");
     render(
       <StrictMode>
@@ -621,70 +610,36 @@ describe("SettingsScreen — timezone auto-set", () => {
       </StrictMode>,
     );
     const form = await screen.findByRole("form", { name: "Preferences" });
-    expect(field(form, "Timezone").value).toBe("America/New_York");
-    expect(writes()).toEqual([
-      { method: "PATCH", path: SETTINGS_PATH, body: { timezone: "America/New_York", timezone_configured: true } },
-    ]);
-  });
-
-  it("an admin clearing the timezone is not re-set by the browser zone, even after a reopen", async () => {
-    mockBrowserZone("America/New_York");
-    const form = await renderForm();
-    fireEvent.change(field(form, "Timezone"), { target: { value: "" } });
-    fireEvent.click(within(form).getByRole("button", { name: "Save preferences" }));
-    await screen.findByText("Preferences saved.");
-    expect(writes().map((w) => w.body)).toEqual([
-      { timezone: "America/New_York", timezone_configured: true },
-      { timezone: "", timezone_configured: true },
-    ]);
-    const reloaded = screen.getByRole("form", { name: "Preferences" });
-    expect(field(reloaded, "Timezone").value).toBe("");
-
-    // Close and reopen: the screen re-fetches "" but the choice persisted.
-    cleanup();
-    const reopened = await renderForm();
-    expect(field(reopened, "Timezone").value).toBe("");
-    expect(writes()).toHaveLength(2);
-  });
-
-  it("an empty timezone the admin chose is never auto-set", async () => {
-    mockBrowserZone("America/New_York");
-    settings = { ...settings, timezone_configured: true };
-    const form = await renderForm();
     expect(field(form, "Timezone").value).toBe("");
     expect(writes()).toEqual([]);
   });
 
-  it("a set timezone is shown and never overwritten by the browser zone", async () => {
+  it("a stored timezone is shown as stored, never replaced by the browser zone", async () => {
     mockBrowserZone("America/New_York");
-    settings = { ...DEFAULT_SETTINGS, timezone: "Europe/Dublin", timezone_configured: false };
+    settings = { ...DEFAULT_SETTINGS, timezone: "Europe/Dublin" };
     const form = await renderForm();
     expect(field(form, "Timezone").value).toBe("Europe/Dublin");
     expect(writes()).toEqual([]);
   });
 
-  it.each([
-    ["nothing", undefined],
-    ["an empty zone", ""],
-    ["an unknown zone", "Etc/Unknown"],
-    ["a non-IANA zone", "not a zone"],
-  ])("detection returning %s leaves the field empty and sends nothing", async (_case, zone) => {
-    mockBrowserZone(zone);
+  it("saving another field sends only that field, never a timezone", async () => {
+    mockBrowserZone("America/New_York");
     const form = await renderForm();
-    expect(field(form, "Timezone").value).toBe("");
-    expect(screen.queryByTestId("preferences-message")).toBeNull();
-    expect(writes()).toEqual([]);
+    fireEvent.change(field(form, "Planning horizon (days)"), { target: { value: "21" } });
+    fireEvent.click(within(form).getByRole("button", { name: "Save preferences" }));
+    await screen.findByText("Preferences saved.");
+    expect(writes().map((w) => w.body)).toEqual([{ horizon_days: 21 }]);
+    expect(settings.timezone).toBe("");
   });
 
-  it("a rejected auto-set shows why and leaves the field empty for manual entry", async () => {
+  it("an admin clearing the timezone saves exactly the empty zone", async () => {
     mockBrowserZone("America/New_York");
-    writeResponse = () => jsonResponse({ detail: "timezone is not known" }, 422);
+    settings = { ...DEFAULT_SETTINGS, timezone: "Europe/Dublin" };
     const form = await renderForm();
-    expect(field(form, "Timezone").value).toBe("");
-    expect(field(form, "Timezone").disabled).toBe(false);
-    expect(screen.getByTestId("preferences-message").textContent).toBe(
-      "The timezone could not be set to America/New_York: timezone is not known",
-    );
-    expect(writes()).toHaveLength(1);
+    fireEvent.change(field(form, "Timezone"), { target: { value: "" } });
+    fireEvent.click(within(form).getByRole("button", { name: "Save preferences" }));
+    await screen.findByText("Preferences saved.");
+    expect(writes().map((w) => w.body)).toEqual([{ timezone: "" }]);
+    expect(field(screen.getByRole("form", { name: "Preferences" }), "Timezone").value).toBe("");
   });
 });

admin/src/settings/SettingsScreen.tsx

@@ -5,9 +5,8 @@
  * household's child profiles. Every write refetches the list.
  *
  * Preferences: the household settings (planning horizon, day rollover,
- * timezone, notifications). Save patches only the changed fields. A timezone
- * the admin never chose is set once, on load, to the browser's own zone;
- * saving the timezone (even clearing it) marks it chosen, so it sticks.
+ * timezone, notifications). Save patches only the changed fields. The
+ * timezone is only ever set by the admin saving it here.
  *
  * One write at a time across both sections.
  */
@@ -291,19 +290,6 @@ export const COMMON_TIMEZONES = [
   "Pacific/Auckland",
 ];
 
-/**
- * The browser's own IANA zone — the location-derived default for an unset
- * household timezone — or "" when it is missing or not a usable zone name.
- */
-export function detectTimezone(): string {
-  try {
-    const zone = Intl.DateTimeFormat().resolvedOptions().timeZone;
-    return typeof zone === "string" && zone !== "Etc/Unknown" && IANA_ZONE.test(zone) ? zone : "";
-  } catch {
-    return "";
-  }
-}
-
 /** The form's working copy: the number is text so it can be mid-edit. */
 type PreferencesDraft = Omit<HouseholdSettings, "horizon_days"> & { horizon_days: string };
 
@@ -342,9 +328,6 @@ function buildChanges(draft: PreferencesDraft, loaded: HouseholdSettings): Setti
   for (const key of Object.keys(loaded) as (keyof HouseholdSettings)[]) {
     if (next[key] !== loaded[key]) (changes as Record<string, unknown>)[key] = next[key];
   }
-  // An explicit choice — including "" (the API host's local time) — must
-  // persist, or the next load would auto-set the browser's zone over it.
-  if ("timezone" in changes) changes.timezone_configured = true;
   if (Object.keys(changes).length === 0) return "No changes to save.";
   return changes;
 }
@@ -574,8 +557,6 @@ export default function SettingsScreen({ onClose }: { onClose: () => void }) {
   } | null>(null);
   // A ref, not state: two taps in one frame must not both see `busy === null`.
   const inFlight = useRef(false);
-  // The never-chosen-timezone auto-set fires at most once per screen.
-  const timezoneAutoSet = useRef(false);
   const screenRef = useRef<HTMLDivElement>(null);
   const titleRef = useRef<HTMLHeadingElement>(null);
   const addRef = useRef<HTMLButtonElement>(null);
@@ -620,29 +601,8 @@ export default function SettingsScreen({ onClose }: { onClose: () => void }) {
     let cancelled = false;
     setPreferences({ kind: "loading" });
     fetchSettings()
-      .then(async (settings) => {
-        if (cancelled) return;
-        // Never chosen: adopt the browser's zone before the form shows, so
-        // nothing the admin enters can be overwritten by it. An empty zone the
-        // admin chose (timezone_configured) is left alone.
-        const unchosen = settings.timezone === "" && !settings.timezone_configured;
-        const detected = unchosen ? detectTimezone() : "";
-        if (!detected || timezoneAutoSet.current) {
-          setPreferences({ kind: "ready", settings });
-          return;
-        }
-        timezoneAutoSet.current = true;
-        try {
-          const saved = await updateSettings({ timezone: detected, timezone_configured: true });
-          if (!cancelled) setPreferences({ kind: "ready", settings: saved });
-        } catch (error) {
-          if (cancelled) return;
-          setPreferences({ kind: "ready", settings });
-          setPreferencesMessage({
-            kind: "error",
-            text: errorMessage(error, `The timezone could not be set to ${detected}`),
-          });
-        }
+      .then((settings) => {
+        if (!cancelled) setPreferences({ kind: "ready", settings });
       })
       .catch((error: unknown) => {
         if (cancelled) return;