Fix student profile dates not saving

Native date pickers blur/refocus the window, which triggered a React Query
refetch mid-edit and wiped the in-progress date. Disable refetchOnWindowFocus,
and make profile/academics edits work on a snapshot with functional state
updates so a background refetch can't clobber input.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/routes/_authenticated/students.$id.tsx

@@ -159,9 +159,13 @@ function ProfileTab({ studentId, canEdit, isAdmin }: { studentId: string; canEdi
     queryKey: ["classes"],
     queryFn: async () => (await supabase.from("classes").select("id, name").order("name")).data ?? [],
   });
-  const [form, setForm] = useState<Record<string, unknown> | null>(null);
-  const c = (form ?? s) as Record<string, unknown> | null;
-  const upd = (k: string, v: unknown) => setForm({ ...(c as Record<string, unknown>), [k]: v });
+  // In edit mode we work on a snapshot (`form`) taken when Edit is pressed, so a
+  // background refetch can never clobber in-progress input. Functional updates
+  // avoid stale-closure races.
+  const [form, setForm] = useState<Record<string, unknown>>({});
+  const startEdit = () => { setForm({ ...(s as Record<string, unknown>) }); setEditing(true); };
+  const c = (editing ? form : s) as Record<string, unknown> | null;
+  const upd = (k: string, v: unknown) => setForm((f) => ({ ...f, [k]: v }));
   const dismissal = (c?.dismissal_methods as string[]) ?? [];
   const toggleDismissal = (v: string) => upd("dismissal_methods", dismissal.includes(v) ? dismissal.filter((x) => x !== v) : [...dismissal, v]);
 
@@ -180,7 +184,7 @@ function ProfileTab({ studentId, canEdit, isAdmin }: { studentId: string; canEdi
       const { error } = await supabase.from("students").update(payload as never).eq("id", studentId);
       if (error) throw error;
     },
-    onSuccess: () => { toast.success("Profile saved"); qc.invalidateQueries({ queryKey: ["student", studentId] }); setForm(null); setEditing(false); },
+    onSuccess: () => { toast.success("Profile saved"); qc.invalidateQueries({ queryKey: ["student", studentId] }); setEditing(false); },
     onError: (e: Error) => toast.error(e.message),
   });
 
@@ -192,7 +196,7 @@ function ProfileTab({ studentId, canEdit, isAdmin }: { studentId: string; canEdi
   if (!editing) {
     return (
       <div className="bg-card border rounded-lg p-6 space-y-6 mt-4">
-        <div className="flex justify-end"><EditToggle editing={editing} setEditing={setEditing} canEdit={canEdit} /></div>
+        <div className="flex justify-end">{canEdit && <Button size="sm" variant="outline" onClick={startEdit}><Pencil className="h-4 w-4 mr-1" /> Edit</Button>}</div>
         <Section title="Student">
           <ViewRow label="First name" value={val("first_name")} />
           <ViewRow label="Last name" value={val("last_name")} />
@@ -281,7 +285,7 @@ function ProfileTab({ studentId, canEdit, isAdmin }: { studentId: string; canEdi
       </Section>
       <div className="flex gap-2">
         <Button onClick={() => save.mutate()} disabled={save.isPending}>{save.isPending ? "Saving…" : "Save profile"}</Button>
-        <Button variant="ghost" onClick={() => { setForm(null); setEditing(false); }}>Cancel</Button>
+        <Button variant="ghost" onClick={() => setEditing(false)}>Cancel</Button>
       </div>
     </div>
   );
@@ -513,9 +517,10 @@ function AcademicsTab({ studentId, canEdit }: { studentId: string; canEdit: bool
     queryKey: ["student", studentId],
     queryFn: async () => (await supabase.from("students").select("*").eq("id", studentId).single()).data,
   });
-  const [form, setForm] = useState<Record<string, unknown> | null>(null);
-  const c = (form ?? s) as Record<string, unknown> | null;
-  const upd = (k: string, v: unknown) => setForm({ ...(c as Record<string, unknown>), [k]: v });
+  const [form, setForm] = useState<Record<string, unknown>>({});
+  const startEdit = () => { setForm({ ...(s as Record<string, unknown>) }); setEditing(true); };
+  const c = (editing ? form : s) as Record<string, unknown> | null;
+  const upd = (k: string, v: unknown) => setForm((f) => ({ ...f, [k]: v }));
   const val = (k: string) => (c?.[k] as string) ?? "";
   const { data: logins } = useQuery({
     queryKey: ["curriculum", studentId],
@@ -530,7 +535,7 @@ function AcademicsTab({ studentId, canEdit }: { studentId: string; canEdit: bool
       }).eq("id", studentId);
       if (error) throw error;
     },
-    onSuccess: () => { toast.success("Saved"); qc.invalidateQueries({ queryKey: ["student", studentId] }); setForm(null); },
+    onSuccess: () => { toast.success("Saved"); qc.invalidateQueries({ queryKey: ["student", studentId] }); },
     onError: (e: Error) => toast.error(e.message),
   });
   const addLogin = useMutation({
@@ -543,7 +548,7 @@ function AcademicsTab({ studentId, canEdit }: { studentId: string; canEdit: bool
 
   return (
     <div className="space-y-6 mt-4">
-      <div className="flex justify-end"><EditToggle editing={editing} setEditing={setEditing} canEdit={canEdit} /></div>
+      <div className="flex justify-end"><EditToggle editing={editing} setEditing={(v) => (v ? startEdit() : setEditing(false))} canEdit={canEdit} /></div>
 
       <div className="bg-card border rounded-lg p-6 space-y-4">
         {!editing ? (