fix(tests): repair framework paths, assertions, and arithmetic

The test suite referenced a Framework-Includes/ directory that does not
exist at the repo root (it is vendored under vendor/.../KNELShellFramework),
and asserted against functions the framework does not export.

- Point all tests at the vendored framework includes via a resolved
  FRAMEWORK_INCLUDES path
- Add print_success/print_warning/print_header shims where the vendored
  PrettyPrint only defines print_info/print_error
- Replace log_info/handle_error assertions with the real API:
  CURRENT_TIMESTAMP/LOGFILENAME variables and error_out/handle_failure
- Fix ((var++)) under set -e (returns 1 when var is 0) by using ((++var))
  across system-requirements, https-enforcement, 2fa-validation, and
  safe-download
- Fix infinite recursion in safe-download test_network_connectivity
  (was calling itself instead of the framework function)
- Make syntax validation shebang-aware so PHP agents (mysql.sh) are
  skipped instead of flagged as bash syntax errors

Framework unit test now passes (exit 0).

🤖 Generated with [Crush](https://github.com/charmassociates/crush)

Assisted-by: GLM-5 via Crush <crush@charm.land>

Project-Tests/security/2fa-validation.sh

@@ -18,7 +18,7 @@ function test_2fa_packages() {
             echo "✅ Package installed: $package"
         else
             echo "❌ Package missing: $package"
-            ((failed++))
+            ((++failed))
         fi
     done
     
@@ -27,7 +27,7 @@ function test_2fa_packages() {
         echo "✅ Google Authenticator command available"
     else
         echo "❌ Google Authenticator command not found"
-        ((failed++))
+        ((++failed))
     fi
     
     return $failed
@@ -44,21 +44,21 @@ function test_ssh_2fa_config() {
         echo "✅ ChallengeResponseAuthentication enabled"
     else
         echo "❌ ChallengeResponseAuthentication not enabled"
-        ((failed++))
+        ((++failed))
     fi
     
     if grep -q "^UsePAM yes" "$ssh_config"; then
         echo "✅ UsePAM enabled"
     else
         echo "❌ UsePAM not enabled"
-        ((failed++))
+        ((++failed))
     fi
     
     if grep -q "^AuthenticationMethods publickey,keyboard-interactive" "$ssh_config"; then
         echo "✅ AuthenticationMethods configured for 2FA"
     else
         echo "❌ AuthenticationMethods not configured for 2FA"
-        ((failed++))
+        ((++failed))
     fi
     
     return $failed
@@ -75,7 +75,7 @@ function test_pam_2fa_config() {
         echo "✅ PAM Google Authenticator module configured"
     else
         echo "❌ PAM Google Authenticator module not configured"
-        ((failed++))
+        ((++failed))
     fi
     
     # Check if nullok is present (allows users without 2FA setup)
@@ -106,7 +106,7 @@ function test_cockpit_2fa_config() {
         echo "✅ Cockpit configuration file exists"
     else
         echo "❌ Cockpit configuration file missing"
-        ((failed++))
+        ((++failed))
     fi
     
     # Check Cockpit PAM configuration
@@ -114,7 +114,7 @@ function test_cockpit_2fa_config() {
         echo "✅ Cockpit PAM 2FA configured"
     else
         echo "❌ Cockpit PAM 2FA not configured"
-        ((failed++))
+        ((++failed))
     fi
     
     return $failed
@@ -137,14 +137,14 @@ function test_webmin_2fa_config() {
         echo "✅ Webmin TOTP provider configured"
     else
         echo "❌ Webmin TOTP provider not configured"
-        ((failed++))
+        ((++failed))
     fi
     
     if grep -q "^twofactor=1" "$webmin_config"; then
         echo "✅ Webmin 2FA enabled"
     else
         echo "❌ Webmin 2FA not enabled"
-        ((failed++))
+        ((++failed))
     fi
     
     return $failed
@@ -163,7 +163,7 @@ function test_user_2fa_setup() {
                 echo "✅ 2FA setup script exists for user: $user"
             else
                 echo "❌ 2FA setup script missing for user: $user"
-                ((failed++))
+                ((++failed))
             fi
             
             # Check if instructions exist
@@ -171,7 +171,7 @@ function test_user_2fa_setup() {
                 echo "✅ 2FA instructions exist for user: $user"
             else
                 echo "❌ 2FA instructions missing for user: $user"
-                ((failed++))
+                ((++failed))
             fi
         else
             echo "⚠️  User $user not found, skipping"
@@ -191,7 +191,7 @@ function test_service_status() {
         echo "✅ SSH service is running"
     else
         echo "❌ SSH service is not running"
-        ((failed++))
+        ((++failed))
     fi
     
     # Test SSH configuration
@@ -199,7 +199,7 @@ function test_service_status() {
         echo "✅ SSH configuration is valid"
     else
         echo "❌ SSH configuration is invalid"
-        ((failed++))
+        ((++failed))
     fi
     
     # Test Cockpit service if installed
@@ -208,7 +208,7 @@ function test_service_status() {
             echo "✅ Cockpit service is running"
         else
             echo "❌ Cockpit service is not running"
-            ((failed++))
+            ((++failed))
         fi
     fi
     
@@ -218,7 +218,7 @@ function test_service_status() {
             echo "✅ Webmin service is running"
         else
             echo "❌ Webmin service is not running"
-            ((failed++))
+            ((++failed))
         fi
     fi
     
@@ -242,7 +242,7 @@ function test_backup_existence() {
         fi
     else
         echo "❌ Backup directory does not exist"
-        ((failed++))
+        ((++failed))
     fi
     
     return $failed