Implement major enhancements to plugin manager (v1.2.0 & v1.3.0)

This commit introduces significant improvements and new features to the plugin manager:

- Add plugin discovery system and remote repository support
- Implement plugin update system with digital signature verification
- Enhance plugin lifecycle hooks (PreLoad, PostLoad, PreUnload)
- Improve dependency management with custom version comparison
- Introduce lazy loading for optimized plugin performance
- Implement comprehensive error handling and logging
- Enhance concurrency safety with fine-grained locking
- Add plugin statistics tracking
- Remove external version comparison dependencies
- Improve hot-reload functionality with graceful shutdown
- Add SSH key support for remote repositories
- Implement Redbean server integration for plugin repositories

This update significantly improves the plugin manager's functionality,
security, and performance, providing a more robust and flexible system
for managing plugins in Go applications.

examples/plugins/math/math.go

@@ -2,6 +2,7 @@ package main
 
 import (
     "fmt"
+
     pm "github.com/matt-dunleavy/plugin-manager"
 )
 
@@ -9,9 +10,9 @@ type MathPlugin struct{}
 
 func (p *MathPlugin) Metadata() pm.PluginMetadata {
     return pm.PluginMetadata{
-        Name:         "MathPlugin",
-        Version:      "1.0.0",
-        Dependencies: []string{},
+        Name:    "MathPlugin",
+        Version: "1.0.0",
+        Dependencies: map[string]string{},
     }
 }
 
@@ -21,11 +22,8 @@ func (p *MathPlugin) Init() error {
 }
 
 func (p *MathPlugin) Execute() error {
-    a, b := 10, 5
-    fmt.Printf("Addition: %d + %d = %d\n", a, b, a+b)
-    fmt.Printf("Subtraction: %d - %d = %d\n", a, b, a-b)
-    fmt.Printf("Multiplication: %d * %d = %d\n", a, b, a*b)
-    fmt.Printf("Division: %d / %d = %d\n", a, b, a/b)
+    result := p.Add(5, 3)
+    fmt.Printf("MathPlugin: 5 + 3 = %d\n", result)
     return nil
 }
 
@@ -34,4 +32,23 @@ func (p *MathPlugin) Shutdown() error {
     return nil
 }
 
+func (p *MathPlugin) PreLoad() error {
+    fmt.Println("MathPlugin pre-load")
+    return nil
+}
+
+func (p *MathPlugin) PostLoad() error {
+    fmt.Println("MathPlugin post-load")
+    return nil
+}
+
+func (p *MathPlugin) PreUnload() error {
+    fmt.Println("MathPlugin pre-unload")
+    return nil
+}
+
+func (p *MathPlugin) Add(a, b int) int {
+    return a + b
+}
+
 var Plugin MathPlugin