refactor: vitals architecture - separate baseline vs blood pressure
BREAKING CHANGE: vitals_log split into vitals_baseline + blood_pressure_log
**Architektur-Änderung:**
- Baseline-Vitals (langsam veränderlich, 1x täglich morgens)
→ vitals_baseline (RHR, HRV, VO2 Max, SpO2, Atemfrequenz)
- Kontext-abhängige Vitals (mehrfach täglich, situativ)
→ blood_pressure_log (Blutdruck + Kontext-Tagging)
**Migration 015:**
- CREATE TABLE vitals_baseline (once daily, morning measurements)
- CREATE TABLE blood_pressure_log (multiple daily, context-aware)
- Migrate data from vitals_log → new tables
- Rename vitals_log → vitals_log_backup_pre_015 (safety)
- Prepared for future: glucose_log, temperature_log (commented)
**Backend:**
- NEW: routers/vitals_baseline.py (CRUD + Apple Health import)
- NEW: routers/blood_pressure.py (CRUD + Omron import + context)
- UPDATED: main.py (register new routers, remove old vitals)
- UPDATED: insights.py (query new tables, split template vars)
**Frontend:**
- UPDATED: api.js (new endpoints für baseline + BP)
- UPDATED: Analysis.jsx (add {{bp_summary}} variable)
**Nächster Schritt:**
- Frontend: VitalsPage.jsx refactoren (3 Tabs: Morgenmessung, Blutdruck, Import)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>