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/dashboard.go

@@ -3,9 +3,10 @@ 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 store = model.NewHostStore()
+var hostStore = store.NewHostStore()
 
 var navItems = []fiber.Map{
 	{"ID": "hosts", "Label": "Hosts", "Icon": "server"},
@@ -17,7 +18,7 @@ var navItems = []fiber.Map{
 }
 
 func Dashboard(c *fiber.Ctx) error {
-	hosts := store.All()
+	hosts := hostStore.All()
 	return c.Render("index", fiber.Map{
 		"View":   "hosts",
 		"Title":  "Hosts",
@@ -31,7 +32,7 @@ func Dashboard(c *fiber.Ctx) error {
 func DashboardList(c *fiber.Ctx) error {
 	q := c.Query("q")
 	filter := c.Query("filter", "all")
-	hosts := store.Search(q, filter)
+	hosts := hostStore.Search(q, filter)
 	return c.Render("host_list", fiber.Map{
 		"Hosts":  hosts,
 		"Active": countByStatus(hosts, "active"),
@@ -50,8 +51,8 @@ func CreateHost(c *fiber.Ctx) error {
 		return c.Status(400).SendString("name and ip required")
 	}
 
-	store.Add(name, ip, os, provider, hostType)
-	hosts := store.All()
+	hostStore.Add(name, ip, os, provider, hostType)
+	hosts := hostStore.All()
 	return c.Render("host_list", fiber.Map{
 		"Hosts":  hosts,
 		"Active": countByStatus(hosts, "active"),
@@ -61,8 +62,8 @@ func CreateHost(c *fiber.Ctx) error {
 
 func DeleteHost(c *fiber.Ctx) error {
 	id := c.Params("id")
-	store.Delete(id)
-	hosts := store.All()
+	hostStore.Delete(id)
+	hosts := hostStore.All()
 	return c.Render("host_list", fiber.Map{
 		"Hosts":   hosts,
 		"Active":  countByStatus(hosts, "active"),