Tri-State Relay Service 2.0.0

• Made relay config the single CLI surface for TOML-backed advanced configuration.
• Added relay config set --voice-command, --combiner-command, and --cleanup-retention-minutes.
• Removed the duplicate relay settings command and made relay combiner read-only; use relay config set --combiner-command to change the combiner.
• Preserved 1.1.2 upgrade migration from SQLite settings into config.toml.
• Added BYO voice command playback while keeping app-owned speech, mute, Focus, Ready, and Live safeguards.
• Added Speechify-compatible voice synthesis support for direct builds, including Keychain-based API-key lookup and rate-limit handling.
• Added provider voice configuration with sticky per-line voice IDs and optional stable assignment for new lines.
• Added local spoken-usage counters by provider, model, voice, and line so custom voice cost can be estimated without storing another copy of relay text.
• Added cleanup controls for old relay rows, spoken-usage buckets, and temporary voice audio files.
• Added Settings UI capture and roundtrip verification for release-quality Settings changes.