feat: Connect Trusted Circle invites to real Brevo transactional email sender

feat: Context-aware journal prompts, sleep correlation tracker, and dark/light mode toggle

feat: Weekly Report — Spotify Wrapped-style emotional summary with mood arc, AI narrative, emotion breakdown, and one-click image export

feat: preload AI models on backend startup to reduce latency

feat: implement JWT auth and voice calibration onboarding

Initial commit: InnerVoice MVP