d41c0fd163
Closes the C9 capability gap: driver-manager now honours a per-driver initial_power_state via a new TOML key. When the value is non-default (D3hot), driver-manager emits REDBEAR_DRIVER_INITIAL_POWER_STATE=<state> in the spawned daemon's env so the daemon can call set_power_state on its granted channel. Mirrors Linux's pci_power_state (include/linux/pci.h). Supported values: D0 (default), D3hot. Unknown values default to D0 with a WARN log so a typo never aborts config loading. Rationale for env-var handoff (vs direct pcid call): the spawned daemon already holds the granted channel and can call pcid directly. Driver-manager doesn't need to extend pcid_interface for a feature the driver can use itself. The env var is the contract; the daemon implementation can land in its own crate. DriverConfig gains: - field: initial_power_state: PciPowerState (default D0) - TOML key: initial_power_state = "D3hot" - legacy TOML converter defaults to D0 (no migration path needed) Tests (7 new): - pci_power_state_from_toml_round_trips (D0 / D3hot) - pci_power_state_from_toml_rejects_unknown_values (D1/D2/D3cold/lower-case/empty) - pci_power_state_is_default_for_d0_only - pci_power_state_as_str_matches_linux_pci_power_state_names - load_all_parses_initial_power_state (D3hot from TOML) - load_all_defaults_to_d0_when_initial_power_state_absent - load_all_warns_and_defaults_on_invalid_initial_power_state 132 driver-manager tests pass.