docs(CHANGES): add HooksMixin to new features

why: HooksMixin feature was built but not documented in CHANGES.
what:
- Add HooksMixin section under "New features"
- Document hook methods: set_hook, show_hook, unset_hook
- Document bulk operations: get_hook_indices, get_hook_values,
  set_hooks_bulk, clear_hook, append_hook
- Note HooksMixin availability on Server, Session, Window, Pane

Author: tony

CHANGES

@@ -95,6 +95,24 @@ Added tmux 3.6 to test grid and `TMUX_MAX_VERSION` 3.4 -> 3.6.
   - `suppress_warnings`: `-q`
   - `append`: `-a`
 
+#### Hooks
+
+Added {class}`hooks.HooksMixin` for managing tmux hooks programmatically:
+
+- {meth}`~hooks.HooksMixin.set_hook` - Set a hook with optional index
+- {meth}`~hooks.HooksMixin.show_hook` - Show current value of a hook
+- {meth}`~hooks.HooksMixin.unset_hook` - Remove a hook
+
+Bulk operations API for managing indexed hooks:
+
+- {meth}`~hooks.HooksMixin.get_hook_indices` - Get list of indices that exist for a hook
+- {meth}`~hooks.HooksMixin.get_hook_values` - Get all indexed values as SparseArray
+- {meth}`~hooks.HooksMixin.set_hooks_bulk` - Set multiple indexed hooks at once
+- {meth}`~hooks.HooksMixin.clear_hook` - Unset all indexed values for a hook
+- {meth}`~hooks.HooksMixin.append_hook` - Append at next available index
+
+HooksMixin is available on {class}`Server`, {class}`Session`, {class}`Window`, and {class}`Pane`.
+
 ## libtmux 0.47.0 (2025-11-01)
 
 ### Breaking changes