fix: improve test reliability and reduce verbose logging

This commit addresses CI test failures and improves the development experience:

**Test Reliability Improvements:**
- Fix Java executable detection in integration tests to check direct bin/java
  location first, preventing bin/bin/java path construction errors
- Add proper working directory restoration in test cleanup to prevent
  'getwd: no such file or directory' errors in subsequent tests
- Skip 'bin' directories when searching for nested Java installations
- Add comprehensive Java installation debug test for CI troubleshooting

**Verbose Logging Improvements:**
- Reduce environment variable logging noise by only logging actual changes
- Track original environment variable values to detect meaningful changes
- Eliminate redundant logging of unchanged system environment variables
- Maintain visibility into actual environment modifications made by mvx

**Technical Details:**
- Modified EnvironmentManager to track original values for change detection
- Enhanced findJavaExecutableWithDebug with proper directory traversal logic
- Added createTestEnvironment/cleanupTestEnvironment with directory restoration
- Improved test isolation to prevent cross-test contamination

These changes significantly improve CI reliability and reduce log verbosity
while maintaining full visibility into meaningful environment changes.

Author: gnodet

pkg/tools/environment.go

@@ -11,15 +11,17 @@ import (
 
 // EnvironmentManager provides safe environment variable management with special PATH handling
 type EnvironmentManager struct {
-	envVars  map[string]string
-	pathDirs []string
+	envVars         map[string]string
+	pathDirs        []string
+	originalEnvVars map[string]string // Track original values to detect changes
 }
 
 // NewEnvironmentManager creates a new environment manager
 func NewEnvironmentManager() *EnvironmentManager {
 	return &EnvironmentManager{
-		envVars:  make(map[string]string),
-		pathDirs: []string{},
+		envVars:         make(map[string]string),
+		pathDirs:        []string{},
+		originalEnvVars: make(map[string]string),
 	}
 }
 
@@ -35,6 +37,7 @@ func NewEnvironmentManagerFromMap(envVars map[string]string) *EnvironmentManager
 			}
 		} else {
 			em.envVars[key] = value
+			em.originalEnvVars[key] = value // Track original value
 		}
 	}
 
@@ -46,8 +49,28 @@ func (em *EnvironmentManager) SetEnv(key, value string) {
 	if key == "PATH" {
 		panic("Cannot set PATH directly, use AddToPath() or AppendToPath() instead")
 	}
+
+	// Check if this is a new value or a change
+	oldValue, existed := em.envVars[key]
+	_, hadOriginal := em.originalEnvVars[key]
+
+	// Store the original value if this is the first time we're seeing this key
+	if !hadOriginal {
+		em.originalEnvVars[key] = os.Getenv(key)
+	}
+
 	em.envVars[key] = value
-	util.LogVerbose("Set environment variable %s=%s", key, value)
+
+	// Only log if the value actually changed from the original
+	if !existed {
+		// New variable being set
+		if em.originalEnvVars[key] != value {
+			util.LogVerbose("Set environment variable %s=%s", key, value)
+		}
+	} else if oldValue != value {
+		// Value changed
+		util.LogVerbose("Updated environment variable %s=%s (was: %s)", key, value, oldValue)
+	}
 }
 
 // GetEnv gets an environment variable