feat: Refactor platform.go to extract domain handlers into separate files and retain only shared helpers

- Add package documentation mapping handler files to domains (services/monitoring/deployments/plugins/automation/config/chaos/billing)
- Remove gorm.io/gorm, models, monitoring, and services package imports
- Remove ServicesHandler struct and all methods (List/Get/Restart/Start/Stop/Scale/Logs/Health/PodStatus/Events)
- Remove MonitoringHandler struct and all methods (Metrics/Alerts/Health/Logs)

apps/api-server/internal/handlers/platform_plugins.go

@@ -0,0 +1,97 @@
+package handlers
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+
+	"github.com/nutcas3/telecom-platform/apps/api-server/internal/services"
+)
+
+// PluginsHandler exposes plugin install/lifecycle endpoints.
+type PluginsHandler struct {
+	svc *services.PluginService
+}
+
+// NewPluginsHandler constructs a PluginsHandler.
+func NewPluginsHandler(svc *services.PluginService) *PluginsHandler {
+	return &PluginsHandler{svc: svc}
+}
+
+func (h *PluginsHandler) List(c *gin.Context) {
+	items, err := h.svc.List(c.Request.Context(), services.PluginFilter{
+		Enabled:  parseBoolQuery(c, "enabled"),
+		Type:     c.Query("type"),
+		Category: c.Query("category"),
+	})
+	if err != nil {
+		serverError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"plugins": items, "total": len(items)})
+}
+
+func (h *PluginsHandler) Get(c *gin.Context) {
+	id, ok := parseUintParam(c, "id")
+	if !ok {
+		return
+	}
+	plugin, err := h.svc.Get(c.Request.Context(), id)
+	if err != nil {
+		notFound(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, plugin)
+}
+
+func (h *PluginsHandler) Install(c *gin.Context) {
+	var in services.InstallPluginInput
+	if err := c.ShouldBindJSON(&in); err != nil {
+		badRequest(c, err)
+		return
+	}
+	p, err := h.svc.Install(c.Request.Context(), in)
+	if err != nil {
+		serverError(c, err)
+		return
+	}
+	c.JSON(http.StatusCreated, p)
+}
+
+func (h *PluginsHandler) Uninstall(c *gin.Context) {
+	id, ok := parseUintParam(c, "id")
+	if !ok {
+		return
+	}
+	if err := h.svc.Uninstall(c.Request.Context(), id); err != nil {
+		notFound(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"message": "plugin uninstalled", "id": id})
+}
+
+func (h *PluginsHandler) Enable(c *gin.Context) {
+	id, ok := parseUintParam(c, "id")
+	if !ok {
+		return
+	}
+	p, err := h.svc.SetEnabled(c.Request.Context(), id, true)
+	if err != nil {
+		notFound(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, p)
+}
+
+func (h *PluginsHandler) Disable(c *gin.Context) {
+	id, ok := parseUintParam(c, "id")
+	if !ok {
+		return
+	}
+	p, err := h.svc.SetEnabled(c.Request.Context(), id, false)
+	if err != nil {
+		notFound(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, p)
+}