feat: add last refreshed timestamp to modules and CDN sources

Introduced a new field, last_refreshed_at, to track the last successful update time for modules and CDN sources. Updated the database schema, API responses, and internal logic to support this feature. Enhanced the frontend to display the last refreshed timestamp, improving visibility into the data update status for users.

internal/store/memory.go

@@ -38,7 +38,7 @@ type Memory struct {
 	asEntries   map[string]*ASEntry
 	domainEnt   map[string]*DomainEntry
 	ipRanges    map[string]*IPRangeEntry
-	settings map[string]map[string]any // tenantID -> key -> JSON-compatible value
+	settings    map[string]map[string]any // tenantID -> key -> JSON-compatible value
 	revPrefixes map[string][]PrefixRow
 
 	// DemoIDs valid after SeedDemo()
@@ -61,17 +61,18 @@ type Tenant struct {
 }
 
 type Module struct {
-	ID                   string
-	TenantID             string
-	Type                 string // AS_PREFIXES, CDN_CIDRS, DOMAINS, IP_RANGES
-	Name                 string
-	Enabled              bool
-	RefreshIntervalSec   int    // 0 = unset
-	CronExpr             string // optional cron for scheduler (display / future use)
-	Priority             int
-	DefaultCommunityID   *string
-	DohProfileID         *string
-	DeletedAt            *time.Time
+	ID                 string
+	TenantID           string
+	Type               string // AS_PREFIXES, CDN_CIDRS, DOMAINS, IP_RANGES
+	Name               string
+	Enabled            bool
+	RefreshIntervalSec int    // 0 = unset
+	CronExpr           string // optional cron for scheduler (display / future use)
+	Priority           int
+	DefaultCommunityID *string
+	DohProfileID       *string
+	LastRefreshedAt    *time.Time
+	DeletedAt          *time.Time
 }
 
 type Revision struct {