refactor(container): drop unused dependency_resolver module

DependencyResolver had zero call sites in prod or tests outside the
module itself. The actual install-time dependency check lives in
install.rs::detect_running_deps + check_install_deps; this DAG-walk
solver was never wired up. -268 LoC.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

core/container/src/lib.rs

@@ -1,5 +1,4 @@
 pub mod bitcoin_simulator;
-pub mod dependency_resolver;
 pub mod health_monitor;
 pub mod manifest;
 pub mod podman_client;
@@ -7,7 +6,6 @@ pub mod port_manager;
 pub mod runtime;
 
 pub use bitcoin_simulator::{BitcoinSimulationMode, BitcoinSimulator};
-pub use dependency_resolver::DependencyResolver;
 pub use health_monitor::HealthMonitor;
 pub use manifest::{
     AppManifest, BuildConfig, ContainerConfig, Dependency, DerivedEnv, HealthCheck, HostFacts,