WeftOS kernel layer for clawft.

This crate provides the kernel abstraction layer that sits between the CLI/API surface and clawft-core. It introduces:

• Boot sequence ([boot::Kernel]) -- lifecycle management wrapping AppContext with structured startup/shutdown.
• Process table ([process::ProcessTable]) -- PID-based agent tracking with state machine transitions.
• Service registry ([service::ServiceRegistry]) -- named service lifecycle with health checks.
• IPC ([ipc::KernelIpc]) -- typed message envelopes over the existing MessageBus.
• Capabilities ([capability::AgentCapabilities]) -- permission model for agent processes.
• Health monitoring ([health::HealthSystem]) -- aggregated health checks across all services.
• Console ([console]) -- boot event types and output formatting for the interactive kernel terminal.
• Configuration ([config::KernelConfig]) -- kernel-specific settings embedded in the root config.
• Containers ([container::ContainerManager]) -- sidecar container lifecycle and health integration.
• Applications ([app::AppManager]) -- application manifest parsing, validation, and lifecycle state machine.
• Cluster ([cluster::ClusterMembership]) -- multi-node cluster membership, peer tracking, and health.
• Environments ([environment::EnvironmentManager]) -- governance-scoped dev/staging/prod environments.
• Governance ([governance::GovernanceEngine]) -- three-branch constitutional governance with effect algebra scoring.
• Agency ([agency::Agency]) -- agent-first architecture with roles, spawn permissions, and agent manifests.

Feature Flags

• native (default) -- enables tokio runtime, native file I/O.
• wasm-sandbox -- enables WASM tool runner (Phase K3).
• containers -- enables container manager (Phase K4).
• ecc -- enables ECC cognitive substrate (Phase K3c).