i18n(notes): translate /notes +page.svelte via $_() — header, toolbar, create form, sections

- <title>, page H1, "{n} Notizen" stats counter
- Search placeholder + "+ Neue Notiz" action
- Create form: Titel/Schreibe etwas placeholders + Abbrechen/Erstellen actions
- "Unbenannt" fallback used in mutation + 2 card titles
- Section labels (Angepinnt / Weitere)
- Empty: "Noch keine Notizen." + "Erste Notiz erstellen" action
- Loading: "Laden..."

Baselines: hardcoded 1058 → 1050 (8 cleared); missing-keys baseline unchanged.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/i18n-hardcoded-baseline.json

@@ -270,7 +270,6 @@
 	"apps/mana/apps/web/src/routes/(app)/news/saved/+page.svelte": 1,
 	"apps/mana/apps/web/src/routes/(app)/news/sources/+page.svelte": 1,
 	"apps/mana/apps/web/src/routes/(app)/notes/[id]/+page.svelte": 5,
-	"apps/mana/apps/web/src/routes/(app)/notes/+page.svelte": 8,
 	"apps/mana/apps/web/src/routes/(app)/observatory/+page.svelte": 6,
 	"apps/mana/apps/web/src/routes/(app)/onboarding/+layout.svelte": 3,
 	"apps/mana/apps/web/src/routes/(app)/onboarding/look/+page.svelte": 6,