diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 8802f48..c8912bb 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -10,6 +10,9 @@ on:
       - main
   workflow_dispatch:
 
+permissions:
+  contents: read
+
 env:
   CARGO_TERM_COLOR: always
 
@@ -45,3 +48,15 @@ jobs:
         run: |
           chmod +x ./verify.sh
           ./verify.sh
+
+      - name: Clippy Analysis
+        run: cd server_manager && cargo clippy --all-targets --all-features -- -D warnings
+
+      - name: Unit & Integration Tests
+        run: cd server_manager && cargo test --all-features
+
+      - name: Dependency License & Bans Check
+        run: cd server_manager && cargo deny check
+
+      - name: Vulnerability Audit
+        run: cd server_manager && cargo audit
diff --git a/AUDIT_REPORT.md b/AUDIT_REPORT.md
index 97b5ef8..6538f6c 100644
--- a/AUDIT_REPORT.md
+++ b/AUDIT_REPORT.md
@@ -21,3 +21,11 @@ A comprehensive security and robustness audit of `server_manager` was performed,
 
 ## Next Steps
 All deployed changes have been systematically verified using the project's native contract testing suite (`./verify.sh`), which successfully confirmed functional integrity without introducing performance degradation.
+
+## 4. Remaining Strict Path and Argument Boundary Defenses
+- **Finding (Medium):** The initial audit remediations enforcing absolute paths missed fallbacks in secondary utilities (`df`, `apt-get`, `sysctl`, `systemctl`, `journalctl`, `timedatectl`, `git`) which would still fallback to `$PATH` if the absolute path was absent, re-introducing path substitution vulnerability. Furthermore, argument bounds (`--`) were missing in `systemctl` commands.
+- **Remediation:** Removed string fallbacks for all binary lookups ensuring hard failures if the binary does not exist at the trusted absolute path. Added explicit `--` bounds to `systemctl` arguments to protect against injection.
+
+## 5. Test File Persistence Hazards
+- **Finding (Low):** Raw `std::fs::write` usages remained within `config.rs` and `journal.rs` test suites.
+- **Remediation:** Replaced remaining `fs::write` calls in tests with the project native `atomic_io::atomic_write_str`.
diff --git a/server_manager/src/core/config.rs b/server_manager/src/core/config.rs
index 1d3bca0..9756405 100644
--- a/server_manager/src/core/config.rs
+++ b/server_manager/src/core/config.rs
@@ -116,12 +116,13 @@ mod tests {
         assert!(cfg.disabled_services.is_empty());
 
         let empty_file = temp_dir.join("empty.yaml");
-        fs::write(&empty_file, "   \n  ").unwrap();
+        crate::core::atomic_io::atomic_write_str(&empty_file, "   \n  ", 0o644).unwrap();
         let cfg2 = Config::load_from(&empty_file).unwrap();
         assert!(cfg2.disabled_services.is_empty());
 
         let invalid_file = temp_dir.join("invalid.yaml");
-        fs::write(&invalid_file, ": : invalid yaml :::").unwrap();
+        crate::core::atomic_io::atomic_write_str(&invalid_file, ": : invalid yaml :::", 0o644)
+            .unwrap();
         let err = Config::load_from(&invalid_file);
         assert!(err.is_err());
         assert_eq!(err.unwrap_err().to_string(), "Invalid config YAML");
diff --git a/server_manager/src/core/doctor.rs b/server_manager/src/core/doctor.rs
index 18d7e35..edd1665 100644
--- a/server_manager/src/core/doctor.rs
+++ b/server_manager/src/core/doctor.rs
@@ -339,7 +339,12 @@ pub fn check_disk_space() -> DoctorCheckResult {
     } else if std::path::Path::new("/usr/bin/df").exists() {
         "/usr/bin/df"
     } else {
-        "df"
+        return DoctorCheckResult {
+            name: "Disk Capacity".to_string(),
+            status: CheckStatus::Skipped,
+            message: "df utility not available or disk space query failed".to_string(),
+            details: None,
+        };
     };
     if let Ok(output) = Command::new(df_path).arg("-Pk").arg(".").output() {
         if output.status.success() {
@@ -390,7 +395,12 @@ pub fn check_ntp_sync() -> DoctorCheckResult {
     } else if std::path::Path::new("/bin/timedatectl").exists() {
         "/bin/timedatectl"
     } else {
-        "timedatectl"
+        return DoctorCheckResult {
+            name: "NTP Time Sync".to_string(),
+            status: CheckStatus::Skipped,
+            message: "timedatectl or /etc/localtime not accessible".to_string(),
+            details: None,
+        };
     };
     if let Ok(output) = Command::new(timedatectl_path).arg("status").output() {
         if output.status.success() {
diff --git a/server_manager/src/core/journal.rs b/server_manager/src/core/journal.rs
index 9406695..8abbe74 100644
--- a/server_manager/src/core/journal.rs
+++ b/server_manager/src/core/journal.rs
@@ -303,8 +303,9 @@ mod tests {
         let target_file = temp_dir.join("config.txt");
         let backup_file = temp_dir.join("config.txt.bak");
 
-        fs::write(&target_file, "corrupted state").unwrap();
-        fs::write(&backup_file, "original good state").unwrap();
+        crate::core::atomic_io::atomic_write_str(&target_file, "corrupted state", 0o644).unwrap();
+        crate::core::atomic_io::atomic_write_str(&backup_file, "original good state", 0o644)
+            .unwrap();
 
         let action = CompensatoryAction::RestoreFile {
             path: target_file.clone(),
@@ -345,7 +346,7 @@ mod tests {
 
         let op_id = generate_op_id();
         let target_file = temp_dir.join("target.txt");
-        fs::write(&target_file, "should be deleted").unwrap();
+        crate::core::atomic_io::atomic_write_str(&target_file, "should be deleted", 0o644).unwrap();
 
         let step1 = JournalEntry {
             timestamp: now_iso8601(),
diff --git a/server_manager/src/core/ops.rs b/server_manager/src/core/ops.rs
index 9ad955d..4dac3b7 100644
--- a/server_manager/src/core/ops.rs
+++ b/server_manager/src/core/ops.rs
@@ -76,7 +76,7 @@ impl SystemOps for RealSystemOps {
 
     fn is_service_active(&self, service_name: &str) -> bool {
         Command::new("/usr/bin/systemctl")
-            .args(["is-active", "--quiet", service_name])
+            .args(["is-active", "--quiet", "--", service_name])
             .status()
             .map(|s| s.success())
             .unwrap_or(false)
@@ -84,10 +84,10 @@ impl SystemOps for RealSystemOps {
 
     fn stop_system_service(&self, service_name: &str) -> Result<()> {
         let _ = Command::new("/usr/bin/systemctl")
-            .args(["stop", service_name])
+            .args(["stop", "--", service_name])
             .status();
         let _ = Command::new("/usr/bin/systemctl")
-            .args(["disable", service_name])
+            .args(["disable", "--", service_name])
             .status();
         Ok(())
     }
@@ -97,7 +97,7 @@ impl SystemOps for RealSystemOps {
         let path = if Path::new("/usr/bin/journalctl").exists() {
             "/usr/bin/journalctl"
         } else {
-            "journalctl"
+            bail!("journalctl not found at absolute path /usr/bin/journalctl");
         };
         let status = Command::new(path)
             .arg(&arg)
diff --git a/server_manager/src/core/system.rs b/server_manager/src/core/system.rs
index 8daf448..dacb970 100644
--- a/server_manager/src/core/system.rs
+++ b/server_manager/src/core/system.rs
@@ -45,7 +45,7 @@ pub fn install_dependencies() -> Result<()> {
     let apt_path = if std::path::Path::new("/usr/bin/apt-get").exists() {
         "/usr/bin/apt-get"
     } else {
-        "apt-get"
+        bail!("apt-get not found at absolute path /usr/bin/apt-get");
     };
     let update_status = Command::new(apt_path)
         .env("DEBIAN_FRONTEND", "noninteractive")
@@ -74,7 +74,7 @@ pub fn install_dependencies() -> Result<()> {
     let systemctl_path = if std::path::Path::new("/usr/bin/systemctl").exists() {
         "/usr/bin/systemctl"
     } else {
-        "systemctl"
+        bail!("systemctl not found at absolute path /usr/bin/systemctl");
     };
     let _ = Command::new(systemctl_path)
         .args(["enable", "--now", "fail2ban"])
@@ -222,7 +222,7 @@ fn get_home_device() -> Result<String> {
     } else if std::path::Path::new("/usr/bin/df").exists() {
         "/usr/bin/df"
     } else {
-        "df"
+        bail!("df not found at absolute paths /bin/df or /usr/bin/df");
     };
     let output = Command::new(df_path)
         .arg("-P")
@@ -330,7 +330,7 @@ net.core.wmem_max=1048576
     } else if std::path::Path::new("/usr/sbin/sysctl").exists() {
         "/usr/sbin/sysctl"
     } else {
-        "sysctl"
+        bail!("sysctl not found at absolute paths /sbin/sysctl or /usr/sbin/sysctl");
     };
     let status = Command::new(sysctl_path)
         .arg("--system")
diff --git a/server_manager/src/core/updater.rs b/server_manager/src/core/updater.rs
index 0b12218..62c624b 100644
--- a/server_manager/src/core/updater.rs
+++ b/server_manager/src/core/updater.rs
@@ -32,7 +32,12 @@ pub fn check_for_updates() -> Result<UpdateInfo> {
         let git_path = if std::path::Path::new("/usr/bin/git").exists() {
             "/usr/bin/git"
         } else {
-            "git"
+            return Ok(UpdateInfo {
+                current_version: current,
+                latest_version: latest,
+                update_available: false,
+                release_notes: "Git not found; cannot check for updates.".to_string(),
+            });
         };
         if let Ok(git_output) = Command::new(git_path)
             .args(["describe", "--tags", "--abbrev=0"])
@@ -96,7 +101,7 @@ pub fn self_update() -> Result<String> {
     let git_path = if std::path::Path::new("/usr/bin/git").exists() {
         "/usr/bin/git"
     } else {
-        "git"
+        bail!("git not found at absolute path /usr/bin/git");
     };
     let pull_status = Command::new(git_path)
         .current_dir(repo_dir)
diff --git a/server_manager/src/interface/web.rs b/server_manager/src/interface/web.rs
index 7e8f8ff..9bfef21 100644
--- a/server_manager/src/interface/web.rs
+++ b/server_manager/src/interface/web.rs
@@ -1412,11 +1412,9 @@ async fn toggle_service_in_process(service_name: &str, enable: bool) -> anyhow::
     use crate::core::{config, hardware, lock::ProcessLock, secrets};
 
     // Serialize service mutations with an advisory lock across processes and concurrent requests
-    let _lock = tokio::task::spawn_blocking(|| {
-        ProcessLock::acquire_default_blocking(false)
-    })
-    .await
-    .map_err(|e| anyhow::anyhow!("Task join error acquiring lock: {}", e))??;
+    let _lock = tokio::task::spawn_blocking(|| ProcessLock::acquire_default_blocking(false))
+        .await
+        .map_err(|e| anyhow::anyhow!("Task join error acquiring lock: {}", e))??;
 
     let mut config = config::Config::load_async().await?;
     if enable {