feat: add maxLength constraints to auth and settings form inputs

Gives users immediate client-side feedback and prevents pathologically
long values from being typed. Caps match Zod schema limits where they
exist; email uses the RFC 5321 maximum.

Files touched (5):
- (home)/login/LocalLoginForm.tsx — email → 254
- (home)/register/page.tsx — email → 254
- dashboard/.../user-settings/.../ProfileContent.tsx — display name → 100
- components/settings/general-settings-manager.tsx — search space name → 100
- components/settings/roles-manager.tsx — role name (create+edit dialogs) → 100,
  role description (create+edit dialogs) → 500

Closes #948

surfsense_web/components/settings/general-settings-manager.tsx

@@ -148,6 +148,7 @@ export function GeneralSettingsManager({ searchSpaceId }: GeneralSettingsManager
 						<Label htmlFor="search-space-name">{t("general_name_label")}</Label>
 						<Input
 							id="search-space-name"
+							maxLength={100}
 							placeholder={t("general_name_placeholder")}
 							value={name}
 							onChange={(e) => setName(e.target.value)}