Bump version 0.5.3 -> 0.5.4, add the 0.5.4 CHANGELOG block, refresh uv.lock. Highlights for owners: sol private backup (BYO encrypted backup to your own cloud bucket), the in-journal "your services" switchboard, on-device speaker diarization for local transcription, and speaker name-variant dedup in curation. Removed todos/skills/routines/the daily digest. On Linux the local provider now runs GPU-accelerated via Vulkan (macOS MLX unchanged). Adds the observer loopback self-register endpoint that locks per-stream identity. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>