Add legal pages, ToS acceptance, and alpha banner

- Journal: Impressum (§5 TMG), Terms of Service, GDPR privacy page
- Registration flow: required ToS checkbox, termsAcceptedAt persisted
- Alpha banner on Journal (always visible); alpha badge on Planner hero
- Footer with legal links + GitHub on both apps
- Reduce PII: sendDefaultPii=false, Sentry init only after login (Journal)
- Drop Sentry from Planner (no login, no consent possible)
- Drop localStorage caching from i18n client detection
- Sync SSR i18n resources each request so locale edits HMR without restart

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

apps/journal/app/lib/auth.server.ts

@@ -76,6 +76,7 @@ export async function finishRegistration(
     email,
     username,
     domain,
+    termsAcceptedAt: new Date(),
   });
 
   await db.insert(credentials).values({
@@ -158,7 +159,7 @@ export async function registerWithMagicLink(email: string, username: string): Pr
   const userId = randomUUID();
   const domain = process.env.DOMAIN ?? "localhost";
 
-  await db.insert(users).values({ id: userId, email, username, domain });
+  await db.insert(users).values({ id: userId, email, username, domain, termsAcceptedAt: new Date() });
 
   // Create magic token for verification
   const token = randomBytes(32).toString("base64url");