i18n(broadcast): translate ComposeView via $_() — 4-step wizard end to end

- Header: name input placeholder + aria, "Gespeichert um {time}" timestamp, Schließen/Speichern actions, Speichert… loading state
- Stepper: 4 step labels (Empfänger/Inhalt/Check/Senden)
- Step 2 content form: Betreff/Preheader/Absender-Name/Absender-E-Mail labels + placeholders, Editor placeholder
- Step 3 preflight: heading, 4 check rows (subject set/missing, recipients count, sender, legal address) with conditional warnings, "Lade Einstellungen…"
- Step 4 send states (idle/confirming/sending/done) with strong-tag interpolation via {@html}; counts injected via {n}, subject via {subject}, fromName via {from}
- Default name and error fallbacks routed through $_(); default-name uses untrack() since $state initialiser runs before template

Baselines: hardcoded 1192 → 1181 (11 cleared); missing-keys baseline unchanged.

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

scripts/i18n-hardcoded-baseline.json

@@ -69,7 +69,6 @@
 	"apps/mana/apps/web/src/lib/modules/broadcast/components/SettingsForm.svelte": 3,
 	"apps/mana/apps/web/src/lib/modules/broadcast/editor/Editor.svelte": 3,
 	"apps/mana/apps/web/src/lib/modules/broadcast/ListView.svelte": 8,
-	"apps/mana/apps/web/src/lib/modules/broadcast/views/ComposeView.svelte": 11,
 	"apps/mana/apps/web/src/lib/modules/broadcast/views/DetailView.svelte": 9,
 	"apps/mana/apps/web/src/lib/modules/broadcast/widgets/BroadcastsWidget.svelte": 3,
 	"apps/mana/apps/web/src/lib/modules/calc/ListView.svelte": 1,