feat(notify): bundle KDCO notify with ownership migration

docs/reference/configuration.md

@@ -592,8 +592,9 @@ Built-in `session-notification` support was removed from oh-my-opencode.
 - Removed hook key: `session-notification`
 - Removed config key: `notification.force_enable`
 - Migration automatically cleans both from legacy configs at startup
+- oh-my-opencode now bundles KDCO notify and auto-registers one user-scope bundled notify plugin entry
 
-For session alerts and cmux-related terminal UX, install KDCO `opencode-notify` (`kdco/notify`) in your OpenCode plugin list.
+Do not add separate `kdco/notify` entries manually. Recognized legacy `kdco/notify` entries are migrated to the bundled owner. Custom/unsafe notify entries fail loudly with cleanup guidance to prevent duplicate owners.
 
 `background-notification` is unchanged because it handles parent-session reminder injection for background tasks, not notification transport.
 

docs/reference/features.md

@@ -792,7 +792,7 @@ Hooks intercept and modify behavior at key points in the agent lifecycle across
 | **agent-usage-reminder**     | PostToolUse + Event | Reminds you to leverage specialized agents for better results.                                     |
 | **question-label-truncator** | PreToolUse          | Truncates long question labels in the Question tool UI.                                            |
 
-Session-level OS alerts are now provided by KDCO `opencode-notify` (`kdco/notify`). oh-my-opencode no longer owns built-in `session-notification` transport.
+Session-level OS alerts are provided by a bundled KDCO `opencode-notify` integration managed by oh-my-opencode. Separate external `kdco/notify` plugin installs are not required.
 
 #### Task Management