fix(help): correct broken imports + tighten SupportedLanguage typing

Two unrelated bugs in the @mana/help package surface that together
accounted for ~40 type errors:

Broken component imports
  Ten components inside packages/help/src/components/ were importing
  from `'../types.js'` and `'./content'` — neither path resolves.
  The actual files are at `../ui-types` (where FAQSectionProps,
  FeaturesOverviewProps etc. live) and `../content` (where FAQItem,
  FeatureItem, FAQCategory live). Fix the imports to point at the
  real files. ESM resolution doesn't need `.js` suffixes when
  TypeScript is feeding tsc, and the existing index.ts already
  re-exports under the correct paths.

  Net: -19 type errors across:
    ChangelogEntry, ChangelogSection, ContactSection, FAQItem,
    FAQSection, FeatureCard, FeaturesOverview, GettingStartedGuide,
    HelpSearch, KeyboardShortcuts

content/help/index.ts SupportedLanguage cast
  `getManaHelpContent()` was passing `currentLocale` (typed `string`)
  into FAQ rows that expect a `SupportedLanguage` enum — 9 errors
  from each FAQ row. Add a small `asSupportedLanguage()` guard that
  validates the locale string against the union and falls back to
  'de' for unknown values. Single source of truth lives next to
  the function that needed it.

  Net: -9 type errors.

Combined with the spiral-db dist rebuild (local-only, gitignored)
and the previous Observable migration commit, the total error count
drops from 418 → 115.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/help/src/components/ChangelogEntry.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import type { ChangelogEntryProps } from '../types.js';
+	import type { ChangelogEntryProps } from '../ui-types';
 
 	let { item, translations }: ChangelogEntryProps = $props();
 

packages/help/src/components/ChangelogSection.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import type { ChangelogSectionProps } from '../types.js';
+	import type { ChangelogSectionProps } from '../ui-types';
 	import ChangelogEntry from './ChangelogEntry.svelte';
 
 	let { items, translations, maxItems = 10 }: ChangelogSectionProps = $props();

packages/help/src/components/ContactSection.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import type { ContactSectionProps } from '../types.js';
+	import type { ContactSectionProps } from '../ui-types';
 
 	let { contact, translations }: ContactSectionProps = $props();
 </script>

packages/help/src/components/FAQItem.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import type { FAQItem } from './content';
+	import type { FAQItem } from '../content';
 
 	interface Props {
 		item: FAQItem;

packages/help/src/components/FAQSection.svelte

@@ -1,6 +1,6 @@
 <script lang="ts">
-	import type { FAQItem, FAQCategory } from './content';
-	import type { FAQSectionProps } from '../types.js';
+	import type { FAQItem, FAQCategory } from '../content';
+	import type { FAQSectionProps } from '../ui-types';
 	import FAQItemComponent from './FAQItem.svelte';
 
 	let {

packages/help/src/components/FeatureCard.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import type { FeatureItem } from './content';
+	import type { FeatureItem } from '../content';
 
 	interface Props {
 		item: FeatureItem;

packages/help/src/components/FeaturesOverview.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import type { FeaturesOverviewProps } from '../types.js';
+	import type { FeaturesOverviewProps } from '../ui-types';
 	import FeatureCard from './FeatureCard.svelte';
 
 	let { items, translations }: FeaturesOverviewProps = $props();

packages/help/src/components/GettingStartedGuide.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import type { GettingStartedGuideProps } from '../types.js';
+	import type { GettingStartedGuideProps } from '../ui-types';
 
 	let { items, translations }: GettingStartedGuideProps = $props();
 

packages/help/src/components/HelpSearch.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import type { HelpSearchProps } from '../types.js';
+	import type { HelpSearchProps } from '../ui-types';
 	import type { SearchResult } from '../content';
 	import { createSearcher } from '../search-engine';
 

packages/help/src/components/KeyboardShortcuts.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import type { KeyboardShortcutsProps } from '../types.js';
+	import type { KeyboardShortcutsProps } from '../ui-types';
 
 	let { items, translations }: KeyboardShortcutsProps = $props();