VS Code panel hardcodes the plan-approval buttons to acceptEdits/default, so the CLI's "Yes, and use auto mode" row never appears

## Summary

In the VS Code panel, the plan-approval dialog always offers the same two accept
buttons, **"Yes, and auto-accept"** and **"Yes, and manually approve edits"**, even
when auto mode is available and is the session's configured default. Accepting a plan
therefore always lands the session in `acceptEdits` or `default`, never back in `auto`.

The bundled CLI does supply an auto row for this dialog. The webview never reads it:
its two plan buttons are hardcoded.

## Environment

| | |
|---|---|
| Extension | `anthropic.claude-code` **2.1.273** (darwin-arm64), bundled CLI 2.1.273 |
| Also reproduced on | extension 2.1.272 |
| CLI (terminal install) | 2.1.268 |
| VS Code | 1.137.0 |
| OS | macOS 27.0 (26A428), arm64 |
| Model | `claude-opus-5[1m]` |
| Settings | `permissions.defaultMode: "auto"`, `useAutoModeDuringPlan` left at its default (on) |

## Expected

With auto mode available, the accept row should be **"Yes, and use auto mode"**
(`yes-resume-auto-mode`), which is what the bundled CLI builds and what the terminal
UI shows for the same session.

## Actual

Three fixed rows: `Yes, and auto-accept` / `Yes, and manually approve edits` /
`No, keep planning`. No way to return to auto, so a session that was in auto before
planning silently degrades on every plan approval.

## The CLI does send the auto row

`resources/native-binary/claude` (2.1.273), option builder for the exit-plan dialog
(minified, reformatted):

```js
function SBt({showClearContext:h, isAutoModeAvailable:ee, isBypassPermissionsModeAvailable:ne,
autoModeGateSnapshot:Se, approvalsWithheld:we=!1, ...}) {
let He = Boolean(ee) && Se;
...
if (ne) { /* bypassPermissions row */ }
else if (He) {
let ot = bwt("exit-plan-resume"); // label: "Yes, and use auto mode"
De["yes-resume-auto-mode"] = ot;
Le["yes-resume-auto-mode"] = "auto";
Ie.push({label: ot.node, value: "yes-resume-auto-mode"});
}
else { /* XZ("acceptEdits", {labelVariant:"plan-keep-context"}) */ }
```

with

```js
var Cwn = { workflow: "Yes, and switch to auto mode",
"exit-plan-resume": "Yes, and use auto mode" };
```

## The webview ignores it

`webview/index.js`, same extension build. `G` is the ExitPlanMode branch
(`var UF="ExitPlanMode"`, `G = $.toolName === UF`):

```js
// button 1
x = async () => {
if (Q(), G) { await Z("acceptEdits", !0); ... }
...
}

// button 2
var ZG0 = Object.freeze({type:"setMode", mode:"default", destination:"session"});
t1 = async () => {
let S0 = (G ? [ZG0] : $.suggestions).map(...)
...
}

// labels
let N0 = "Yes"; if (G) N0 = "Yes, and auto-accept"; else if (q) N0 = "Submit answers";
... G ? "Yes, and manually approve edits" :
```

For ExitPlanMode the webview replaces `$.suggestions` (the rows the CLI built) with a
frozen `setMode: "default"`, and button 1 calls `acceptEdits` unconditionally. Nothing
in the bundle can produce the auto row:

```console
$ grep -o 'type:"setMode",mode:"[a-zA-Z]*"' webview/index.js | sort | uniq -c
1 type:"setMode",mode:"default"
$ grep -c "use auto mode" webview/index.js
0
```

## Not an availability problem

The gate is open in every window, including during the failing dialog:

```
[auto-mode] verifyAutoModeGateAccess: enabledState=enabled disabledBySettings=false
model=claude-opus-5[1m] modelSupported=true disableFastModeBreakerFires=false
carouselAvailable=true canEnterAuto=true
```

Auto is also present and selectable in the panel's own permission-mode picker at the
same time. Only the plan dialog lacks it.

## Reproduction

1. Set `permissions.defaultMode: "auto"` in user settings.
2. Open the VS Code panel, enter plan mode, let the model produce a plan.
3. Approve it.
4. Check the permission mode afterwards: `acceptEdits` (button 1) or `default`
(button 2). The same session approved from the terminal UI offers
"Yes, and use auto mode" and stays in auto.

## Workaround

Pick button 2, then switch back to Auto by hand via shift+tab or the mode picker.
Button 1 moves away from auto in the other direction.

## Suggested fix

Render the accept rows the CLI already sends (`$.suggestions` / `keepContextRows`)
for ExitPlanMode instead of the hardcoded `acceptEdits` / `default` pair, the same way
the panel renders suggestion rows for ordinary permission prompts.

## Related

- #94682 — the panel drops Auto from the permission-mode *picker* while the host logs
`canEnterAuto=true`. Same underlying theme (the webview decides for itself instead of
using what the host sends), different surface. In this report the picker is fine.
- #90571 — same picker, via a model alias missing from the models list.
- #93207 — iOS plan approval sends `setMode auto` and discards `prePlanMode`.

Start in webview/index.js at the ExitPlanMode branch and compare its hardcoded button handlers with the CLI options and the panel's ordinary suggestion-row rendering. Trace $.suggestions or keepContextRows and verify that the dialog displays the host-provided auto row and leaves the session in auto after approval.

Written by the indexing model from the issue text.