feat: convert ssh tunnels into a plugin

src/backend/database/db/schema.ts

@@ -459,23 +459,6 @@ export const sshCredentialUsage = sqliteTable(
   ],
 );
 
-export const c2sTunnelPresets = sqliteTable("c2s_tunnel_presets", {
-  id: integer("id").primaryKey({ autoIncrement: true }),
-  userId: text("user_id")
-    .notNull()
-    .references(() => users.id, { onDelete: "cascade" }),
-  name: text("name").notNull(),
-  config: text("config").notNull(),
-  platform: text("platform"),
-  computerName: text("computer_name"),
-  createdAt: text("created_at")
-    .notNull()
-    .default(sql`CURRENT_TIMESTAMP`),
-  updatedAt: text("updated_at")
-    .notNull()
-    .default(sql`CURRENT_TIMESTAMP`),
-});
-
 export const sshFolders = sqliteTable(
   "ssh_folders",
   {