feat: initial commit — uptime monitor (forked from go-upkeep)

Go-based uptime monitor with SQLite/Postgres storage, TUI dashboard,
SSH server, alerting, and clustering support.

internal/models/models.go

@@ -0,0 +1,47 @@
+package models
+
+import "time"
+
+type Site struct {
+	ID              int
+	Name            string
+	URL             string
+	Type            string // "http" or "push"
+	Token           string // Secure Token
+	Interval        int
+	AlertID         int
+	CheckSSL        bool
+	ExpiryThreshold int
+	
+	MaxRetries      int
+	FailureCount    int
+
+	Status          string
+	StatusCode      int
+	Latency         time.Duration
+	CertExpiry      time.Time
+	HasSSL          bool
+	LastCheck       time.Time
+	SentSSLWarning  bool 
+}
+
+type AlertConfig struct {
+	ID       int
+	Name     string
+	Type     string
+	Settings map[string]string
+}
+
+type User struct {
+	ID        int
+	Username  string
+	PublicKey string
+	Role      string 
+}
+
+// Phase 5: Backup Structure
+type Backup struct {
+	Sites  []Site        `json:"sites"`
+	Alerts []AlertConfig `json:"alerts"`
+	Users  []User        `json:"users"`
+}