Workspace (client) spec create + edit

- File -> New workspace... (name -> template -> edit -> create & switch)
- File -> Edit current workspace... (edit View/Root/Options as spec text)
- Backend p4 client -o/-i

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/p4.ts

@@ -106,6 +106,8 @@ export const p4 = {
   // built-in editor: write text back to a depot file's working copy
   writeDepot: (depot: string, content: string) => invoke<void>("write_depot", { depot, content }),
   switchClient: (client: string) => invoke<P4Info>("p4_switch_client", { client }),
+  clientSpec: (client: string) => invoke<string>("p4_client_spec", { client }),
+  clientSave: (spec: string) => invoke<string>("p4_client_save", { spec }),
   users: () => invoke<User[]>("p4_users"),
   groups: (user = "") => invoke<{ group?: string }[]>("p4_groups", { user }),
   groupMember: (group: string, user: string, add: boolean) => invoke<string>("p4_group_member", { group, user, add }),