"""Fester toolchain integration modules.

Provides adapters for alternative/sovereign toolchains that can be
used alongside the default ccache+distcc+gcc pipeline.

Provider architecture (table-driven, PEP 868):
  - **btc.py**       — BTC.sh sovereign-forged toolchain (forensic stamps)
  - **chroot.py**    — Generic chroot + distro-specific providers:
                         native, buildroot, sourcemage, gentoo, lede, lunar

Selection priority (first match wins):
  1. Per-node ``toolchain.provider`` override
  2. Global ``toolchain.provider`` in config.yaml
  3. BTC (if btc.enabled is true and golden image exists)
  4. Native host gcc fallback
"""