Release 0.3.0-delta DSP audio routing graph editor — major feature release. UI: - New 'Audio Routing' panel in dashboard - Rete.js v2 + Svelte 4 node-graph editor - 14 DSP effects + draggable palette - Live param inspector + per-node level meters - WebSocket-driven live updates with origin echo suppression - Bus creation flow Backend: - audio.toml schema v1 (replaces mic_config.toml; auto-migrates on boot) - Per-bus DSP chains via BusEffectChainRegistry (zero-alloc hot path) - Multi-deck MusicManager (4 decks, ≤1 librespot) - Deck-aware OnSongEnd / FireAtSongPosition cue triggers - Music routing through RoutingMatrix - 13 REST mutation endpoints + 5 new Audio* WS Event variants - All 10 fixture projects boot from audio.toml - Perf bench: full workload at 236µs (under 1% of 25ms frame budget)