Bug: FileSystemError unhandled-rejection with relative 'output:' file path

Description

The extension throws an unhandled rejection error when attempting to resolve a filesystem provider on virtual output channels using relative paths.

Full Log Error:
2026-05-28T14:34:54.990Z pid=18039 [extension] rules-loaded | rss=1310.2MB heap=960.6MB/1089.9MB ext=23.6MB | builtin=45 personal=0 project=0 pending=0 root=/home/.tools
2026-05-28T14:34:54.990Z pid=18039 [extension] metrics-loaded | rss=1310.2MB heap=960.6MB/1089.9MB ext=23.6MB | builtin=10 personal=0 project=0
2026-05-28T14:34:58.110Z pid=18039 [extension] command-open | rss=1310.6MB heap=963.3MB/1090.1MB ext=23.6MB
2026-05-28T14:34:58.110Z pid=18039 [panel] create-new | rss=1310.6MB heap=963.3MB/1090.1MB ext=23.6MB
2026-05-28T14:34:58.111Z pid=18039 [panel] constructor | rss=1310.6MB heap=963.3MB/1090.1MB ext=23.6MB
2026-05-28T14:34:58.111Z pid=18039 [panel] loadData-start | rss=1310.6MB heap=963.4MB/1090.1MB ext=23.6MB
2026-05-28T14:34:58.113Z pid=18039 [panel] logs-dirs-found | rss=1310.6MB heap=963.4MB/1090.1MB ext=23.6MB | count=3
2026-05-28T14:34:58.113Z pid=18039 [parser] child-start | rss=1310.6MB heap=963.4MB/1090.1MB ext=23.6MB | attempt=1 logsDirs=3 worker=/home/rgr/.vscode-insiders/extensions/ai-engineer-coach.ai-engineer-coach-0.1.0/dist/parse-worker.js maxOldSpaceMb=30720
2026-05-28T14:34:58.223Z pid=18039 [parser] child-progress-phase | rss=1310.6MB heap=963.5MB/1090.1MB ext=23.6MB | attempt=1 phase=1 detail=Computing directory fingerprints
2026-05-28T14:34:58.268Z pid=18039 [parser] child-progress-phase | rss=1310.6MB heap=963.5MB/1090.1MB ext=23.6MB | attempt=1 phase=2 detail=Cold parse
2026-05-28T14:36:11.201Z pid=18039 [extension-host] unhandled-rejection | rss=612.8MB heap=400.2MB/408.4MB ext=16.7MB | Error (FileSystemError): Unable to resolve filesystem provider with relative file path 'output:extension-output-ai-engineer-coach.ai-engineer-coach-%231-AI Engineer Coach'
at or._handleError (file:///usr/share/code-insiders/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:502:22201)
at Object.stat (file:///usr/share/code-insiders/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:502:19119)
...
2026-05-28T14:40:55.009Z pid=18039 [extension-host] unhandled-rejection | rss=720.3MB heap=439.7MB/487.2MB ext=16.8MB | Error (FileSystemError): Unable to resolve filesystem provider with relative file path 'output:extension-output-ai-engineer-coach.ai-engineer-coach-%231-AI Engineer Coach'
at or._handleError (file:///usr/share/code-insiders/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:502:22201)
at Object.stat (file:///usr/share/code-insiders/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:502:19119)
2026-05-28T14:40:55.052Z pid=18039 [extension-host] unhandled-rejection | rss=728.1MB heap=447.9MB/494.9MB ext=16.8MB | Error (FileSystemError): Unable to resolve filesystem provider with relative file path 'output:extension-output-ai-engineer-coach.ai-engineer-coach-%231-AI Engineer Coach'
at or._handleError (file:///usr/share/code-insiders/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:502:22201)
at Object.stat (file:///usr/share/code-insiders/resources/app/out/vs/workbench/api/node/extensionHostProcess.
js:502:19119)
2026-05-28T14:42:23.282Z pid=18039 [extension-host] unhandled-rejection | rss=706.1MB heap=431.5MB/501.7MB ext=17.2MB | Error (FileSystemError): Unable to resolve filesystem provider with relative file path 'output:extension-output-ai-engineer-coach.ai-engineer-coach-%231-AI Engineer Coach'
at or._handleError (file:///usr/share/code-insiders/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:502:22201)
at Object.stat (file:///usr/share/code-insiders/resources/app/out/vs/workbench/api/node/extensionHostProcess.js:502:19119)
2026-05-28T14:42:23.285Z pid=18039 [parser] child-exit | rss=706.1MB heap=431.5MB/501.7MB ext=17.2MB | attempt=2 code=null signal=SIGABRT
2026-05-28T14:42:23.285Z pid=18039 [panel] loadData-error | rss=706.1MB heap=431.5MB/501.7MB ext=17.2MB | Error: Child process killed by SIGABRT
2026-05-28T14:44:03.266Z pid=47687 [extension] rules-loaded | rss=669.8MB heap=411.1MB/452.4MB ext=18.0MB | builtin=45 personal=0 project=0 pending=0 root=/home/.tools
2026-05-28T14:44:03.266Z pid=47687 [extension] metrics-loaded | rss=669.8MB heap=411.1MB/452.4MB ext=18.0MB | builtin=10 personal=0 project=0
2026-05-28T14:44:19.889Z pid=47687 [extension] command-reload | rss=1379.6MB heap=969.0MB/1081.2MB ext=23.6MB
2026-05-28T14:44:19.889Z pid=47687 [panel] create-new | rss=1379.6MB heap=969.0MB/1081.2MB ext=23.6MB
2026-05-28T14:44:19.890Z pid=47687 [panel] constructor | rss=1379.6MB heap=969.0MB/1081.2MB ext=23.6MB
2026-05-28T14:44:19.890Z pid=47687 [panel] loadData-start | rss=1379.6MB heap=969.0MB/1081.2MB ext=23.6MB
2026-05-28T14:44:19.892Z pid=47687 [panel] logs-dirs-found | rss=1379.6MB heap=969.1MB/1081.2MB ext=23.6MB | count=3
2026-05-28T14:44:19.892Z pid=47687 [parser] child-start | rss=1379.6MB heap=969.1MB/1081.2MB ext=23.6MB | attempt=1 logsDirs=3 worker=/home/rgr/.vscode-insiders/extensions/ai-engineer-coach.ai-engineer-coach-0.1.0/dist/parse-worker.js maxOldSpaceMb=30720
2026-05-28T14:44:20.016Z pid=47687 [parser] child-progress-phase | rss=1379.9MB heap=969.5MB/1081.2MB ext=23.6MB | attempt=1 phase=1 detail=Computing directory fingerprints
2026-05-28T14:44:20.028Z pid=47687 [parser] child-progress-phase | rss=1379.9MB heap=969.6MB/1081.2MB ext=23.6MB | attempt=1 phase=2 detail=Cold parse
2026-05-28T14:44:29.815Z pid=47687 [parser] child-exit | rss=632.6MB heap=367.2MB/374.1MB ext=16.7MB | attempt=1 code=null signal=SIGABRT
2026-05-28T14:44:29.815Z pid=47687 [parser] child-retry | rss=632.6MB heap=367.2MB/374.1MB ext=16.7MB | reason=Child process killed by SIGABRT maxOldSpaceMb=30720
2026-05-28T14:44:29.815Z pid=47687 [parser] child-start | rss=632.6MB heap=367.2MB/374.1MB ext=16.7MB | attempt=2 logsDirs=3 worker=/home/rgr/.vscode-insiders/extensions/ai-engineer-coach.ai-engineer-coach-0.1.0/dist/parse-worker.js maxOldSpaceMb=30720
2026-05-28T14:44:29.917Z pid=47687 [parser] child-progress-phase | rss=632.7MB heap=367.5MB/374.4MB ext=16.7MB | attempt=2 phase=1 detail=Computing directory fingerprints
2026-05-28T14:44:29.929Z pid=47687 [parser] child-progress-phase | rss=632.7MB heap=367.6MB/374.4MB ext=16.7MB | attempt=2 phase=2 detail=Cold parse
2026-05-28T14:44:39.850Z pid=47687 [parser] child-exit | rss=596.7MB heap=372.1MB/379.7MB ext=18.8MB | attempt=2 code=null signal=SIGABRT
2026-05-28T14:44:39.850Z pid=47687 [panel] loadData-error | rss=596.7MB heap=372.1MB/379.7MB ext=18.8MB | Error: Child process killed by SIGABRT

Steps to Reproduce

1. Open VS Code Insiders.
2. Activate the AI Engineer Coach extension.
3. Open or switch to the extension's output channel window/logs, or trigger an extension command that generates logs.
4. Check the Developer Tools console/extension host logs to observe the unhandled rejection crash.

Expected Behavior

The extension should properly handle or filter out custom virtual URI schemes (like output:) and ensure that relative paths are not passed directly into filesystem methods like fs.stat.

Extension Version

0.1.0

VS Code Version

1.22.0-insiders

Operating System

Ubuntu 26

Start by tracing the extension's output-channel and log-loading flow from the reported extension-host, panel, and parser events, then locate filesystem calls such as fs.stat handling the output: URI. Done means virtual output schemes and relative paths no longer produce an unhandled rejection or crash during the listed reproduction steps.