Phase 1: tier demo landing pages, CRM schema, playbooks

- templates/landing: two self-contained demos (Tier A barbershop / Google stack,
  Tier B physio / self-hosted) + chooser page
- sheets/SCHEMA.md: Google Sheets CRM workbook spec
- playbooks: per-client setup checklists for both tiers
- README + .gitignore
- Demos avoid unverifiable claims (no "DSGVO-konform", no "Ende-zu-Ende")

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,20 @@
+# dependencies / build
+node_modules/
+dist/
+.astro/
+*.log
+
+# secrets — never commit credentials
+.env
+.env.*
+*.secret
+credentials/
+stacks/**/.env
+
+# n8n local data
+n8n/.n8n/
+n8n/*-credentials.json
+
+# OS
+.DS_Store
+Thumbs.db