First working milestone of the Rust rewrite. Implements the two
foundational systems every other component depends on:
- TOML-based layered config (beds.toml + env.toml override) replacing
the PHP XML config system, fully deserialized into typed structs via
serde — no runtime string key lookups, shape enforced at compile time
- Structured logging via tracing + tracing-journald, with optional
console mirror, initialized from config before any services start
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>