docs(plan): update documentation regarding supporting editing of plan files during plan approval

docs/cli/plan-mode.md

@@ -107,6 +107,10 @@ structure, and consultation level are proportional to the task's complexity:
     and formally request approval.
     - **Approve:** Exit Plan Mode and start implementation.
     - **Iterate:** Provide feedback to refine the plan.
+    - **Refine manually:** Press **Ctrl + X** to open the plan file in your
+      [preferred external editor]. This allows you to manually refine the plan
+      steps before approval. The CLI will automatically refresh and show the
+      updated plan after you save and close the editor.
 
 For more complex or specialized planning tasks, you can
 [customize the planning workflow with skills](#customizing-planning-with-skills).
@@ -305,3 +309,4 @@ performance. You can disable this automatic switching in your settings:
   https://github.com/google-gemini/gemini-cli/blob/main/packages/core/src/policy/policies/plan.toml
 [auto model]: /docs/reference/configuration.md#model-settings
 [model routing]: /docs/cli/telemetry.md#model-routing
+[preferred external editor]: /docs/reference/configuration.md#general

docs/reference/keyboard-shortcuts.md

@@ -87,12 +87,12 @@ available combinations.
 
 #### Text Input
 
-| Action                                         | Keys                                                                                      |
-| ---------------------------------------------- | ----------------------------------------------------------------------------------------- |
-| Submit the current prompt.                     | `Enter (no Shift, Alt, Ctrl, Cmd)`                                                        |
-| Insert a newline without submitting.           | `Ctrl + Enter`<br />`Cmd + Enter`<br />`Alt + Enter`<br />`Shift + Enter`<br />`Ctrl + J` |
-| Open the current prompt in an external editor. | `Ctrl + X`                                                                                |
-| Paste from the clipboard.                      | `Ctrl + V`<br />`Cmd + V`<br />`Alt + V`                                                  |
+| Action                                                     | Keys                                                                                      |
+| ---------------------------------------------------------- | ----------------------------------------------------------------------------------------- |
+| Submit the current prompt.                                 | `Enter (no Shift, Alt, Ctrl, Cmd)`                                                        |
+| Insert a newline without submitting.                       | `Ctrl + Enter`<br />`Cmd + Enter`<br />`Alt + Enter`<br />`Shift + Enter`<br />`Ctrl + J` |
+| Open the current prompt or the plan in an external editor. | `Ctrl + X`                                                                                |
+| Paste from the clipboard.                                  | `Ctrl + V`<br />`Cmd + V`<br />`Alt + V`                                                  |
 
 #### App Controls
 

packages/cli/src/config/keyBindings.ts

@@ -489,7 +489,7 @@ export const commandDescriptions: Readonly<Record<Command, string>> = {
   [Command.SUBMIT]: 'Submit the current prompt.',
   [Command.NEWLINE]: 'Insert a newline without submitting.',
   [Command.OPEN_EXTERNAL_EDITOR]:
-    'Open the current prompt in an external editor.',
+    'Open the current prompt or the plan in an external editor.',
   [Command.PASTE_CLIPBOARD]: 'Paste from the clipboard.',
 
   // App Controls