[type-safety] HealthBar: drop `as ThemeMode` cast; type `permission` as NotificationPermission

[fedorovvvv]

Source: PRD-018 SC-2 audit, Type [C1] + [W2] + [C2].

C1: blunt as ThemeMode cast

template/src/widgets/health-bar/ui/HealthBar.svelte:97

onValueChange={(v) => themeStore.setMode(v as ThemeMode)}

v is string (what ToggleGroup type="single" declares for its callback). If bits-ui ever fires '' (deselection) or any future value, themeStore.setMode('') becomes a runtime fault with no compile-time signal.

Fix:

onValueChange={(v) => {
  if (v === 'auto' || v === 'light' || v === 'dark') themeStore.setMode(v);
}}

Or — better — parameterise ToggleGroup<TValue> so the callback is (next: ThemeMode) => void.

W2: permission typed as string

template/src/widgets/health-bar/ui/HealthBar.svelte:16

let permission = $state<string>('default');

Should be $state<NotificationPermission>('default') (DOM lib type, union 'default' | 'granted' | 'denied'). Then the comparisons at lines 43, 111, 114 become exhaustive.

C2: legacy $props<{...}>() syntax

template/src/widgets/health-bar/ui/HealthBar.svelte:11

Other migrated widgets use interface Props { … }; let { … }: Props = $props();. HealthBar uses the legacy generic-argument form. Fix: lift to a Props interface like Filters.svelte:10.

Acceptance

• npm run check clean.
• No as ThemeMode or generic-argument $props<> in the file.
• permission typed NotificationPermission.

Audit traceability

• Reviewer: TypeScript-pro, score 7/10

[fedorovvvv]

Fixed in branch `develop` as part of PRD-019 Wave 1.

What changed (`template/src/widgets/health-bar/ui/HealthBar.svelte`)

C1 — `as ThemeMode` cast dropped. Replaced with an `isThemeMode` type guard:
```ts
function isThemeMode(v: string): v is ThemeMode {
return v === 'auto' || v === 'light' || v === 'dark';
}
…
onValueChange={(v) => { if (isThemeMode(v)) themeStore.setMode(v); }}
```
A stray `''` (deselection) or any future bits-ui value now no-ops instead of corrupting state.

W2 — `permission` typed correctly. Now `NotificationPermission | 'unsupported'` to match the actual return type of `notificationPermission()` (which returns `'unsupported'` for sandboxed iframes).

C2 — Legacy `$props<{}>()` syntax lifted. Now uses the canonical `interface Props { … }` form like `Filters.svelte`.

Acceptance

• `npm run check` clean.
• No `as ThemeMode` or generic-argument `$props<>` in the file.
• `permission` typed `NotificationPermission | 'unsupported'`.

[fedorovvvv]

Resolved by PR #100 (merged into develop as merge commit 6f498b9). Will reach main with the next release/v* cycle.