Add tmux pane management for background agent sessions (#1094)

* feat(config): add TmuxConfigSchema for tmux subagent pane management

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* feat(shared): add tmux module structure

* feat(shared/tmux): implement tmux pane utilities

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* test(tmux-subagent): add TmuxSessionManager tests (TDD RED)

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* feat(tmux-subagent): implement TmuxSessionManager

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* feat(integration): wire TmuxSessionManager with 500ms delay

- Task 5: Add 500ms delay in BackgroundManager after session creation
- Task 6: Wire TmuxSessionManager event handlers (session.created/deleted)
- Both changes integrate tmux pane management into plugin lifecycle

Co-authored-by: Sisyphus <ultrawork@oh-my-opencode>

---------

Co-authored-by: justsisyphus <justsisyphus@users.noreply.github.com>
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
Co-authored-by: Sisyphus <ultrawork@oh-my-opencode>

src/config/index.ts

@@ -9,6 +9,8 @@ export {
   SisyphusAgentConfigSchema,
   ExperimentalConfigSchema,
   RalphLoopConfigSchema,
+  TmuxConfigSchema,
+  TmuxLayoutSchema,
 } from "./schema"
 
 export type {
@@ -23,4 +25,6 @@ export type {
   ExperimentalConfig,
   DynamicContextPruningConfig,
   RalphLoopConfig,
+  TmuxConfig,
+  TmuxLayout,
 } from "./schema"