feat(tmux): add session isolation mode for subagent panes

src/config/schema/tmux.ts

@@ -8,13 +8,21 @@ export const TmuxLayoutSchema = z.enum([
   "even-vertical", // all panes vertical stack
 ])
 
+export const TmuxIsolationSchema = z.enum([
+  "inline",   // panes split in user's current window (legacy behavior)
+  "window",   // panes created in a separate tmux window (same session)
+  "session",  // panes created in a detached tmux session (full isolation)
+])
+
 export const TmuxConfigSchema = z.object({
   enabled: z.boolean().default(false),
   layout: TmuxLayoutSchema.default("main-vertical"),
   main_pane_size: z.number().min(20).max(80).default(60),
   main_pane_min_width: z.number().min(40).default(120),
   agent_pane_min_width: z.number().min(20).default(40),
+  isolation: TmuxIsolationSchema.default("session"),
 })
 
 export type TmuxConfig = z.infer<typeof TmuxConfigSchema>
 export type TmuxLayout = z.infer<typeof TmuxLayoutSchema>
+export type TmuxIsolation = z.infer<typeof TmuxIsolationSchema>