[Crash Report]

**Describe the Crash**
Explain clearly what you were doing when the crash occurred.

**Steps To Reproduce**
Describe precisely how the crash occurred, step by step, starting with a new editor window.
1. Open the Graphite editor at https://editor.graphite.art
2. Had 3 files open, working on 1
3. Was a copied path from one of the other files
4. Saved - Worked Fine
5. Export - Crashes
6. Reload - Export works

Had it happen 4 times now, different file numbers open, but always the one with the path I am copying and an extra.

**Additional Details**
Provide any further information or context that you think would be helpful in fixing the issue. Screenshots or video can be linked or attached to this issue.

**Browser and OS**
Firefox 148, Windows 10 or 11

**Stack Trace**
Copied from the crash dialog in the Graphite editor:

```
panicked at editor/src/messages/dialog/export_dialog/export_dialog_message_handler.rs:125:99:
called `Option::unwrap()` on a `None` value

Wp/<@https://editor.graphite.art/assets/index-BPxHMP7l.js:988:1384
w@https://editor.graphite.art/assets/index-BPxHMP7l.js:970:73924
handleJsMessage@https://editor.graphite.art/assets/index-BPxHMP7l.js:970:74072
yp/e<@https://editor.graphite.art/assets/index-BPxHMP7l.js:970:74496
ep/o.wbg.__wbg_call_833bed5770ea2041/<@https://editor.graphite.art/assets/index-BPxHMP7l.js:970:14904
Ke@https://editor.graphite.art/assets/index-BPxHMP7l.js:969:6188
ep/o.wbg.__wbg_call_833bed5770ea2041@https://editor.graphite.art/assets/index-BPxHMP7l.js:970:14874
graphite_wasm.wasm._ZN13graphite_wasm10editor_api12EditorHandle27send_frontend_message_to_js17hb921190d4deab3e4E@https://editor.graphite.art/assets/graphite_wasm_bg-BjpNRPYb.wasm:wasm-function[807]:0x44c00d
graphite_wasm.wasm._ZN4core3ops8function2Fn4call17hce3f3ec565af54aaE@https://editor.graphite.art/assets/graphite_wasm_bg-BjpNRPYb.wasm:wasm-function[19280]:0xe83259
graphite_wasm.wasm._ZN3std9panicking20rust_panic_with_hook17he3dc6abfb01fb415E@https://editor.graphite.art/assets/graphite_wasm_bg-BjpNRPYb.wasm:wasm-function[10755]:0xd5f456
graphite_wasm.wasm._ZN4core9panicking9panic_fmt17h808dbde205a89691E@https://editor.graphite.art/assets/graphite_wasm_bg-BjpNRPYb.wasm:wasm-function[15108]:0xdfde2c
graphite_wasm.wasm._ZN4core9panicking5panic17hd2efa669b7ab826eE@https://editor.graphite.art/assets/graphite_wasm_bg-BjpNRPYb.wasm:wasm-function[14567]:0xdf5256
graphite_wasm.wasm._ZN4core6option13unwrap_failed17h314697a0a1a32358E@https://editor.graphite.art/assets/graphite_wasm_bg-BjpNRPYb.wasm:wasm-function[18739]:0xe69632
graphite_wasm.wasm._ZN15graphite_editor8messages6layout13utility_types13layout_widget18DialogLayoutHolder23send_dialog_to_frontend17h47e0ec46f512a826E@https://editor.graphite.art/assets/graphite_wasm_bg-BjpNRPYb.wasm:wasm-function[3351]:0x9c9226
graphite_wasm.wasm._ZN301_$LT$graphite_editor..messages..dialog..dialog_message_handler..DialogMessageHandler$u20$as$u20$graphite_editor..utility_traits..MessageHandler$LT$graphite_editor..messages..dialog..dialog_message..DialogMessage$C$graphite_editor..messages..dialog..dialog_message_handler..DialogMessageContext$GT$$GT$15process_message17h7d2e8de18e682455E@https://editor.graphite.art/assets/graphite_wasm_bg-BjpNRPYb.wasm:wasm-function[734]:0x3fccde
graphite_wasm.wasm._ZN3std6thread5local17LocalKey$LT$T$GT$4with17h2ff9d597868cd633E@https://editor.graphite.art/assets/graphite_wasm_bg-BjpNRPYb.wasm:wasm-function[4879]:0xaf533a
graphite_wasm.wasm._ZN13graphite_wasm10editor_api12EditorHandle19widget_value_update17h05622066a71b4373E@https://editor.graphite.art/assets/graphite_wasm_bg-BjpNRPYb.wasm:wasm-function[3019]:0x96a615
graphite_wasm.wasm.editorhandle_widgetValueCommitAndUpdate externref shim multivalue shim@https://editor.graphite.art/assets/graphite_wasm_bg-BjpNRPYb.wasm:wasm-function[15111]:0xdfe11c
widgetValueCommitAndUpdate@https://editor.graphite.art/assets/index-BPxHMP7l.js:970:6185
action@https://editor.graphite.art/assets/index-BPxHMP7l.js:1012:80330
U@https://editor.graphite.art/assets/index-BPxHMP7l.js:1012:56910
pe@https://editor.graphite.art/assets/index-BPxHMP7l.js:1012:59491
i@https://editor.graphite.art/assets/index-BPxHMP7l.js:1012:51084
at/<@https://editor.graphite.art/assets/index-BPxHMP7l.js:17:1178
at@https://editor.graphite.art/assets/index-BPxHMP7l.js:17:1165
k@https://editor.graphite.art/assets/index-BPxHMP7l.js:1012:12957
```

Start in editor/src/messages/dialog/export_dialog/export_dialog_message_handler.rs at line 125, then follow the export dialog flow that reaches DialogLayoutHolder::send_dialog_to_frontend. Reproduce the crash with multiple files and a copied path before export; done means exporting no longer panics in that scenario.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.