Sprint 6: JSON file persistence + real SSH terminal + V1 crypto/knownhosts integration

- go.mod replace directive for git.tukangketik.id/swanadiva/hostkeeper → ../../v1
- store/ package: JSON file persistence for hosts, snippets, keys, settings
  (~/Library/Application Support/hostkeeper/v2/)
- model SSH fields: Hostname, Port, Username, AuthType, Password, KeyID
- sshconn/ package: real SSH client via golang.org/x/crypto/ssh
- Terminal WS: real SSH connection with fallback to mock shell
- Dynamic host list in terminal (server-rendered JSON script tag)
- All mock data defaults removed from model packages
- Settings persist via store/settings.go

app/backend/internal/handler/settings.go

@@ -3,23 +3,24 @@ package handler
 import (
 	"github.com/gofiber/fiber/v2"
 	"git.tukangketik.id/swanadiva/hostkeeper/v2/internal/model"
+	"git.tukangketik.id/swanadiva/hostkeeper/v2/internal/store"
 )
 
 var deviceStore = model.NewDeviceStore()
-var configStore = model.NewConfigStore()
+var settingsStore = store.NewSettingsStore()
 
 func Settings(c *fiber.Ctx) error {
 	return c.Render("settings", fiber.Map{
 		"View":      "settings",
 		"Title":     "Settings",
-		"Config":    configStore.Get(),
+		"Config":    settingsStore.Get(),
 		"Devices":   deviceStore.All(),
 		"NavItems":  navItems,
 	})
 }
 
 func UpdateConfig(c *fiber.Ctx) error {
-	cfg := configStore.Get()
+	cfg := settingsStore.Get()
 	if v := c.FormValue("theme"); v != "" { cfg.Theme = v }
 	if v := c.FormValue("fontSize"); v != "" { cfg.FontSize = parseInt(v, 14) }
 	if v := c.FormValue("scrollback"); v != "" { cfg.Scrollback = parseInt(v, 5000) }
@@ -29,7 +30,7 @@ func UpdateConfig(c *fiber.Ctx) error {
 	cfg.BellEnabled = c.FormValue("bellEnabled") == "on"
 	cfg.AutoReconnect = c.FormValue("autoReconnect") == "on"
 	cfg.BlinkCursor = c.FormValue("blinkCursor") == "on"
-	configStore.Update(cfg)
+	settingsStore.Update(cfg)
 	return c.Redirect("/settings", 303)
 }