[Feature Request] Add support for /usage and /feedback commands in VSCode extension

Bug Description
Not all of the /commands are available through VSCode. It would be nice if they were! For example, I would like to check my /usage while using Claude Code VScode, and I would like to use /feedback while using Claude Code VSCode as well!

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 2.0.58
• Feedback ID: 4544dfc5-f95f-4f5f-9f79-f74bb2f9ff7a

Errors

[{"error":"AggregateError\n    at J2A.from (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:11:14602)\n    at hz.<anonymous> (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:29:10022)\n    at hz.emit (node:events:520:35)\n    at hz.emit (node:domain:489:12)\n    at UF1.<computed> (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:28:1117)\n    at ClientRequest.emit (node:events:520:35)\n    at ClientRequest.emit (node:domain:489:12)\n    at emitErrorEvent (node:_http_client:107:11)\n    at TLSSocket.socketErrorListener (node:_http_client:574:5)\n    at TLSSocket.emit (node:events:508:28)\n    at xVA.request (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:31:2130)\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at async $K0 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:4275:8674)","timestamp":"2025-12-16T19:51:37.512Z"}]