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/unit/safe-download.sh

@@ -5,15 +5,22 @@
 
 set -euo pipefail
 
-PROJECT_ROOT="$(dirname "$(realpath "${BASH_SOURCE[0]}")")/../.."
+PROJECT_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
 
-# Source framework functions
-source "$PROJECT_ROOT/Framework-Includes/SafeDownload.sh"
+# Source framework functions from the vendored KNELShellFramework
+FRAMEWORK_INCLUDES="$PROJECT_ROOT/vendor/git@git.knownelement.com/29418/KNEL/KNELShellFramework/Framework-Includes"
+
+# The vendored PrettyPrint only defines print_info/print_error, but SafeDownload.sh
+# calls print_success/print_warning; define lightweight shims before sourcing.
+function print_success() { echo "✅ $1"; }
+function print_warning()  { echo "⚠️  $1"; }
+
+source "$FRAMEWORK_INCLUDES/SafeDownload.sh"
 
 function test_network_connectivity() {
     echo "🔍 Testing network connectivity..."
-    
-    if test_network_connectivity; then
+
+    if check_url_accessibility "https://github.com"; then
         echo "✅ Network connectivity test passed"
         return 0
     else
@@ -37,7 +44,7 @@ function test_url_accessibility() {
             echo "✅ URL accessible: $url"
         else
             echo "❌ URL not accessible: $url"
-            ((failed++))
+            ((++failed))
         fi
     done
     
@@ -60,20 +67,20 @@ function test_safe_download() {
             echo "✅ Downloaded file exists and has content"
         else
             echo "❌ Downloaded file is missing or empty"
-            ((failed++))
+            ((++failed))
         fi
         
         # Cleanup
         rm -f "$test_dest"
     else
         echo "❌ Safe download failed"
-        ((failed++))
+        ((++failed))
     fi
     
     # Test download with invalid URL
     if safe_download "https://invalid.example.com/nonexistent" "/tmp/test-invalid-$$" 2>/dev/null; then
         echo "❌ Invalid URL download should have failed"
-        ((failed++))
+        ((++failed))
     else
         echo "✅ Invalid URL download failed as expected"
     fi
@@ -97,13 +104,13 @@ function test_checksum_verification() {
         echo "✅ Correct checksum verification passed"
     else
         echo "❌ Correct checksum verification failed"
-        ((failed++))
+        ((++failed))
     fi
     
     # Test incorrect checksum
     if verify_checksum "$test_file" "invalid_checksum" 2>/dev/null; then
         echo "❌ Incorrect checksum should have failed"
-        ((failed++))
+        ((++failed))
     else
         echo "✅ Incorrect checksum verification failed as expected"
     fi
@@ -111,7 +118,7 @@ function test_checksum_verification() {
     # Test missing file
     if verify_checksum "/tmp/nonexistent-file-$$" "$expected_checksum" 2>/dev/null; then
         echo "❌ Missing file checksum should have failed"
-        ((failed++))
+        ((++failed))
     else
         echo "✅ Missing file checksum verification failed as expected"
     fi
@@ -143,7 +150,7 @@ function test_batch_download() {
                 echo "✅ Batch file downloaded: $(basename "$file")"
             else
                 echo "❌ Batch file missing: $(basename "$file")"
-                ((failed++))
+                ((++failed))
             fi
         done
         
@@ -153,7 +160,7 @@ function test_batch_download() {
         done
     else
         echo "❌ Batch download failed"
-        ((failed++))
+        ((++failed))
     fi
     
     return $failed
@@ -172,7 +179,7 @@ function test_config_backup_and_restore() {
     # Test safe config download (this will fail with invalid URL, triggering restore)
     if safe_config_download "https://invalid.example.com/config" "$test_config" ".test-backup" 2>/dev/null; then
         echo "❌ Invalid config download should have failed"
-        ((failed++))
+        ((++failed))
     else
         echo "✅ Invalid config download failed as expected"
         
@@ -181,7 +188,7 @@ function test_config_backup_and_restore() {
             echo "✅ Original config was restored after failed download"
         else
             echo "❌ Original config was not restored properly"
-            ((failed++))
+            ((++failed))
         fi
     fi
     
@@ -199,14 +206,14 @@ function test_download_error_handling() {
     # Test download with missing parameters
     if safe_download "" "/tmp/test" 2>/dev/null; then
         echo "❌ Download with empty URL should have failed"
-        ((failed++))
+        ((++failed))
     else
         echo "✅ Download with empty URL failed as expected"
     fi
     
     if safe_download "https://example.com" "" 2>/dev/null; then
         echo "❌ Download with empty destination should have failed"
-        ((failed++))
+        ((++failed))
     else
         echo "✅ Download with empty destination failed as expected"
     fi
@@ -214,7 +221,7 @@ function test_download_error_handling() {
     # Test download to read-only location (should fail)
     if safe_download "https://github.com" "/test-readonly-$$" 2>/dev/null; then
         echo "❌ Download to read-only location should have failed"
-        ((failed++))
+        ((++failed))
     else
         echo "✅ Download to read-only location failed as expected"
     fi