GitLab Duo Agent Platform (beta) runs into error while processing request, not usable afterwards
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### Checklist
<!--Please test the latest versions, that will remove the possibility that you see a bug that is fixed in a newer version.-->
- [x] I'm using the latest version of the extension ([see the latest version in the right column of this page](https://marketplace.visualstudio.com/items?itemName=GitLab.gitlab-workflow))
- Extension version: _6.49.2_
- [x] I'm using the latest VS Code version ([find the latest version here](https://github.com/microsoft/vscode/releases))
- VS Code version: _Version: 1.104.2 (system setup) Commit: e3a5acfb517a443235981655413d566533107e92 Date: 2025-09-24T11:21:37.073Z Electron: 37.3.1 ElectronBuildId: 12404162 Chromium: 138.0.7204.235 Node.js: 22.18.0 V8: 13.8.258.31-electron.0 OS: Windows_NT x64 10.0.26100_
- [x] I'm using a supported version of GitLab ([see README for the supported version](https://gitlab.com/gitlab-org/gitlab-vscode-extension/-/blob/main/README.md#minimum-supported-version))
- GitLab version: _happens on `gitlab.com`_
### Summary
<!--Summarize the bug encountered concisely-->
After a bit of usage, GitLab Duo Agent Platform (Beta) reports a generic error and can't be used anymore.
See below for logs.
Restarting VS Code doesn't fix the problem.
### Steps to reproduce
<!--How one can reproduce the issue - this is very important-->
Just use GitLab Duo Agent Platform for a while, no particular pattern, previously it worked for a couple of messages. Now, it's failing constantly and can't even process the initial message in a new session.
### What is the current _bug_ behavior?
<!--What actually happens-->
GitLab Duo Agent Platform just states: "There was an error processing your request. Please try again or contact support if the issue persists."
### What is the expected _correct_ behavior?
<!--What you should see instead-->
GitLab Duo Agent Platform should process the message and keep responding to each subsequent message.
### Relevant logs and/or screenshots
<!--Logs can be found by running `GitLab: Show extension logs` command (using `cmd+shift+p`). Please enable `"gitlab.debug": true` in your `settings.json`. Debug mode will improve error stack traces and adds debug log messages.-->
Sometimes, there are errors related to GraphQL, e.g. `Error fetching workflow: GraphQL request "query: getDuoWorkflowEvents" failed with`
Screenshot:
{width=555 height=453}
The GitLab Workflow output contains many messages like this one:
```
Unable to merge security findings reports.
Cannot read properties of null (reading 'status')
TypeError: Cannot read properties of null (reading 'status')
at hasEmptyReport (/home/me/.vscode-server/extensions/src/desktop/gitlab/security_findings/get_all_security_reports.ts:46:10)
at /home/me/.vscode-server/extensions/src/desktop/gitlab/security_findings/get_all_security_reports.ts:43:79
at Array.filter (<anonymous>)
at validFindingReports (/home/me/.vscode-server/extensions/src/desktop/gitlab/security_findings/get_all_security_reports.ts:43:66)
at ske (/home/me/.vscode-server/extensions/src/desktop/gitlab/security_findings/get_all_security_reports.ts:78:22)
at processTicksAndRejections (node:internal/process/task_queues:105:5)
at Function.getState (/home/me/.vscode-server/extensions/src/desktop/current_branch_refresher.ts:185:28)
at t.refresh (/home/me/.vscode-server/extensions/src/desktop/current_branch_refresher.ts:130:25)
at Timeout._onTimeout (/home/me/.vscode-server/extensions/src/desktop/current_branch_refresher.ts:124:7)
```
### Possible fixes
<!--If you can, link to the line of code that might be responsible for the problem-->
issue