feat(tui): add vim text object bindings (openai#24382)

## Why

Vim mode currently supports some normal-mode operators and motions, but
common text-object combinations like `ciw`, `daw`, `di(`, and
quote/bracket variants are still missing. That makes the composer feel
incomplete for users who expect operator + text object editing to work
inside prompts.

Closes openai#21383.

## What Changed

- Add Vim pending-state support for operator/text-object sequences.
- Add `c` as a normal-mode operator for text objects, so combinations
like `ciw` delete the object and enter insert mode.
- Support word, WORD, delimiter, and quote text objects:
  - `iw`, `aw`, `iW`, `aW`
  - `i(`, `a(`, `i)`, `a)`, `ib`, `ab`
  - `i[`, `a[`, `i]`, `a]`
  - `i{`, `a{`, `i}`, `a}`, `iB`, `aB`
  - `i"`, `a"`, `i'`, `a'`, `i\``, `a\``
- Add configurable keymap entries and keymap picker coverage for the new
Vim text-object context.
- Regenerate the config schema and update keymap picker snapshots.

## How to Test

Manual smoke test:

1. Start Codex with Vim composer mode enabled.
2. Type a draft such as:
   ```text
   alpha beta gamma
   call(foo[bar], {"x": "hello world"})
   say "one \"two\" three" now
   ```
3. Put the cursor on `beta`, press `ciw`, and confirm `beta` is removed
and the composer enters insert mode.
4. Escape back to normal mode, put the cursor on `gamma`, press `daw`,
and confirm `gamma` plus surrounding whitespace is removed.
5. Put the cursor inside `foo[bar]`, press `di[`, and confirm only `bar`
is removed.
6. Put the cursor inside `call(...)`, press `da(`, and confirm the whole
parenthesized section is removed.
7. Put the cursor inside the quoted text, press `ci"`, and confirm the
quote contents are removed and insert mode starts.
8. Verify cancellation does not edit text: press `d` then `Esc`, and
press `d` then `i` then `Esc`.

Targeted tests:

- `cargo test -p codex-tui --lib vim_`
- `cargo nextest run -p codex-tui keymap_setup::tests`

Additional local checks:

- `just write-config-schema`
- `just fmt`
- `just fix -p codex-tui`
- `git diff --check`
- `cargo insta pending-snapshots --manifest-path tui/Cargo.toml`

Local full-suite note: `just test -p codex-tui` ran to completion. The
keymap snapshot failures were expected and accepted. Two unrelated
guardian feature-flag tests still fail locally:
-
`app::tests::update_feature_flags_disabling_guardian_clears_review_policy_and_restores_default`
-
`app::tests::update_feature_flags_disabling_guardian_clears_manual_review_policy_without_history`

`just argument-comment-lint` is currently blocked locally by Bazel
analysis before the lint runs because `compiler-rt` has an empty
`include/sanitizer/*.h` glob in the local Bazel cache. The touched Rust
diff was manually inspected for opaque positional literals.

Author: fcoury-oai

codex-rs/config/src/tui_keymap.rs

@@ -233,6 +233,8 @@ pub struct TuiVimNormalKeymap {
     pub start_delete_operator: Option<KeybindingsSpec>,
     /// Begin yank operator; next key selects motion (`y`).
     pub start_yank_operator: Option<KeybindingsSpec>,
+    /// Begin change operator; next keys select a text object.
+    pub start_change_operator: Option<KeybindingsSpec>,
     /// Cancel a pending operator and return to normal mode.
     pub cancel_operator: Option<KeybindingsSpec>,
 }
@@ -268,10 +270,39 @@ pub struct TuiVimOperatorKeymap {
     pub motion_line_start: Option<KeybindingsSpec>,
     /// Motion: to end of line (`$`).
     pub motion_line_end: Option<KeybindingsSpec>,
+    /// Select an inner text object after an operator.
+    pub select_inner_text_object: Option<KeybindingsSpec>,
+    /// Select an around text object after an operator.
+    pub select_around_text_object: Option<KeybindingsSpec>,
     /// Cancel the pending operator and return to normal mode.
     pub cancel: Option<KeybindingsSpec>,
 }
 
+/// Vim text-object keybindings for modal editing inside text areas.
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, Default, JsonSchema)]
+#[serde(deny_unknown_fields)]
+#[schemars(deny_unknown_fields)]
+pub struct TuiVimTextObjectKeymap {
+    /// Text object: word.
+    pub word: Option<KeybindingsSpec>,
+    /// Text object: whitespace-delimited WORD.
+    pub big_word: Option<KeybindingsSpec>,
+    /// Text object: parentheses.
+    pub parentheses: Option<KeybindingsSpec>,
+    /// Text object: brackets.
+    pub brackets: Option<KeybindingsSpec>,
+    /// Text object: braces.
+    pub braces: Option<KeybindingsSpec>,
+    /// Text object: double quotes.
+    pub double_quote: Option<KeybindingsSpec>,
+    /// Text object: single quotes.
+    pub single_quote: Option<KeybindingsSpec>,
+    /// Text object: backticks.
+    pub backtick: Option<KeybindingsSpec>,
+    /// Cancel the pending text-object command.
+    pub cancel: Option<KeybindingsSpec>,
+}
+
 /// Pager context keybindings for transcript and static overlays.
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, Default, JsonSchema)]
 #[serde(deny_unknown_fields)]
@@ -376,6 +407,8 @@ pub struct TuiKeymap {
     #[serde(default)]
     pub vim_operator: TuiVimOperatorKeymap,
     #[serde(default)]
+    pub vim_text_object: TuiVimTextObjectKeymap,
+    #[serde(default)]
     pub pager: TuiPagerKeymap,
     #[serde(default)]
     pub list: TuiListKeymap,
@@ -562,6 +595,20 @@ mod tests {
         );
     }
 
+    #[test]
+    fn misspelled_vim_text_object_action_is_rejected() {
+        let toml_input = r#"
+            [vim_text_object]
+            double_quotes = "shift-quote"
+        "#;
+        let err = toml::from_str::<TuiKeymap>(toml_input)
+            .expect_err("expected unknown vim text object action");
+        assert!(
+            err.to_string().contains("double_quotes"),
+            "expected error to mention misspelled field, got: {err}"
+        );
+    }
+
     #[test]
     fn removed_backtrack_actions_are_rejected() {
         for (context, action) in [

codex-rs/core/config.schema.json

@@ -2851,6 +2851,7 @@
               "open_line_above": null,
               "open_line_below": null,
               "paste_after": null,
+              "start_change_operator": null,
               "start_delete_operator": null,
               "start_yank_operator": null,
               "yank_line": null
@@ -2867,7 +2868,20 @@
               "motion_word_backward": null,
               "motion_word_end": null,
               "motion_word_forward": null,
+              "select_around_text_object": null,
+              "select_inner_text_object": null,
               "yank_line": null
+            },
+            "vim_text_object": {
+              "backtick": null,
+              "big_word": null,
+              "braces": null,
+              "brackets": null,
+              "cancel": null,
+              "double_quote": null,
+              "parentheses": null,
+              "single_quote": null,
+              "word": null
             }
           },
           "description": "Keybinding overrides for the TUI.\n\nThis supports rebinding selected actions globally and by context. Context bindings take precedence over `global` bindings."
@@ -3518,6 +3532,7 @@
             "open_line_above": null,
             "open_line_below": null,
             "paste_after": null,
+            "start_change_operator": null,
             "start_delete_operator": null,
             "start_yank_operator": null,
             "yank_line": null
@@ -3541,8 +3556,28 @@
             "motion_word_backward": null,
             "motion_word_end": null,
             "motion_word_forward": null,
+            "select_around_text_object": null,
+            "select_inner_text_object": null,
             "yank_line": null
           }
+        },
+        "vim_text_object": {
+          "allOf": [
+            {
+              "$ref": "#/definitions/TuiVimTextObjectKeymap"
+            }
+          ],
+          "default": {
+            "backtick": null,
+            "big_word": null,
+            "braces": null,
+            "brackets": null,
+            "cancel": null,
+            "double_quote": null,
+            "parentheses": null,
+            "single_quote": null,
+            "word": null
+          }
         }
       },
       "type": "object"
@@ -3903,6 +3938,14 @@
           ],
           "description": "Paste after cursor (`p`)."
         },
+        "start_change_operator": {
+          "allOf": [
+            {
+              "$ref": "#/definitions/KeybindingsSpec"
+            }
+          ],
+          "description": "Begin change operator; next keys select a text object."
+        },
         "start_delete_operator": {
           "allOf": [
             {
@@ -4022,6 +4065,22 @@
           ],
           "description": "Motion: to start of next word (`w`)."
         },
+        "select_around_text_object": {
+          "allOf": [
+            {
+              "$ref": "#/definitions/KeybindingsSpec"
+            }
+          ],
+          "description": "Select an around text object after an operator."
+        },
+        "select_inner_text_object": {
+          "allOf": [
+            {
+              "$ref": "#/definitions/KeybindingsSpec"
+            }
+          ],
+          "description": "Select an inner text object after an operator."
+        },
         "yank_line": {
           "allOf": [
             {
@@ -4033,6 +4092,85 @@
       },
       "type": "object"
     },
+    "TuiVimTextObjectKeymap": {
+      "additionalProperties": false,
+      "description": "Vim text-object keybindings for modal editing inside text areas.",
+      "properties": {
+        "backtick": {
+          "allOf": [
+            {
+              "$ref": "#/definitions/KeybindingsSpec"
+            }
+          ],
+          "description": "Text object: backticks."
+        },
+        "big_word": {
+          "allOf": [
+            {
+              "$ref": "#/definitions/KeybindingsSpec"
+            }
+          ],
+          "description": "Text object: whitespace-delimited WORD."
+        },
+        "braces": {
+          "allOf": [
+            {
+              "$ref": "#/definitions/KeybindingsSpec"
+            }
+          ],
+          "description": "Text object: braces."
+        },
+        "brackets": {
+          "allOf": [
+            {
+              "$ref": "#/definitions/KeybindingsSpec"
+            }
+          ],
+          "description": "Text object: brackets."
+        },
+        "cancel": {
+          "allOf": [
+            {
+              "$ref": "#/definitions/KeybindingsSpec"
+            }
+          ],
+          "description": "Cancel the pending text-object command."
+        },
+        "double_quote": {
+          "allOf": [
+            {
+              "$ref": "#/definitions/KeybindingsSpec"
+            }
+          ],
+          "description": "Text object: double quotes."
+        },
+        "parentheses": {
+          "allOf": [
+            {
+              "$ref": "#/definitions/KeybindingsSpec"
+            }
+          ],
+          "description": "Text object: parentheses."
+        },
+        "single_quote": {
+          "allOf": [
+            {
+              "$ref": "#/definitions/KeybindingsSpec"
+            }
+          ],
+          "description": "Text object: single quotes."
+        },
+        "word": {
+          "allOf": [
+            {
+              "$ref": "#/definitions/KeybindingsSpec"
+            }
+          ],
+          "description": "Text object: word."
+        }
+      },
+      "type": "object"
+    },
     "UriBasedFileOpener": {
       "oneOf": [
         {