Phase 0: Rust project scaffolding (M0 complete)

Completed Rust project initialization:
- Cargo.toml with all dependencies (actix-web, tokio, rustls, etc.)
- Project structure (src/, tests/, configs/)
- Module declarations (api, auth, config, jobs, logging, packages, systemd)
- Clippy and rustfmt configured
- Initial lib.rs and main.rs with logging setup
- Config examples (config.yaml.example, whitelist.yaml.example)

Dependencies resolved and project compiles successfully.
Rust toolchain 1.94.1 installed.

src/logging/init.rs

@@ -0,0 +1,44 @@
+//! Logging Initialization
+//!
+//! Sets up tracing with systemd journal and file appender support.
+
+
+use anyhow::Result;
+use tracing_appender::non_blocking::WorkerGuard;
+use tracing_subscriber::{fmt, layer::SubscriberExt, util::SubscriberInitExt, EnvFilter};
+
+
+/// Initialize logging with tracing
+///
+/// Sets up:
+/// - Env-based log level filtering
+/// - JSON formatting for machine readability
+/// - systemd journal integration
+/// - File appender fallback to /var/log/linux_patch_api/
+pub fn init_logging(verbose: bool) -> Result<WorkerGuard> {
+    let log_level = if verbose { "debug" } else { "info" };
+    let filter = EnvFilter::try_from_default_env()
+        .unwrap_or_else(|_| EnvFilter::new(log_level));
+    
+    let file_appender = tracing_appender::rolling::daily("/var/log/linux_patch_api", "audit.log");
+    let (non_blocking, guard) = tracing_appender::non_blocking(file_appender);
+    
+    let file_layer = fmt::layer()
+        .with_writer(non_blocking)
+        .with_ansi(false)
+        .with_target(true)
+        .with_thread_ids(true);
+    
+    let stdout_layer = fmt::layer()
+        .with_writer(std::io::stdout)
+        .with_ansi(true);
+    
+    tracing_subscriber::registry()
+        .with(filter)
+        .with(file_layer)
+        .with(stdout_layer)
+        .try_init()
+        .ok(); // Ignore if already initialized
+    
+    Ok(guard)
+}

src/logging/mod.rs

@@ -0,0 +1,11 @@
+//! Logging Module - Audit logging and tracing
+//!
+//! Handles audit logging as defined in SPEC.md:
+//! - systemd journal integration (primary)
+//! - Optional remote syslog
+//! - Local file fallback (/var/log/linux_patch_api/audit.log)
+//! - 30-day retention with daily rotation
+
+pub mod appender;
+pub mod journal;
+pub mod init;