Desktop app: /connect (BYOK provider flow) is missing entirely — no way to add your own API key from the desktop UI #1041

Environment

• Desktop app 0.1.55 (macOS), bundled CLI command-code 1.82.3
• Command Code account with exhausted credits; user has their own DeepSeek API key and wants to BYOK

What happens

• Typing /connect in the desktop app does nothing — the command palette has no /connect entry. Searching "connect" only surfaces /mcp (its description contains the word "connect").
• The desktop auth screen only supports Command Code account sign-in / Command Code API key. There is no flow anywhere in the desktop UI to paste a third-party provider key (DeepSeek, OpenRouter, etc.).
• The desktop's own error copy tells users to run it anyway: "Your Anthropic sign-in is no longer valid. In the Command Code CLI, run /login anthropic to sign in again or /connect to switch providers, then restart the desktop app." — a command the desktop UI doesn't have.

What works (CLI)

• The bundled CLI 1.82.3 has the full /connect flow (BYOK wizard, 150+ prefilled providers, keys stored in ~/.commandcode/auth.json).
• Hand-written ~/.commandcode/providers.json entries are honored: cmd --list-models shows DeepSeek (byok) with its models.

Evidence it's a build gap, not a config problem

• The desktop renderer's hardcoded slash-command list (workspace-screen bundle) includes /mcp, /model, /compact, etc. — no provider-connect entry.
• The string "Connect to AI providers" appears in the CLI/harness bundles on disk but nowhere in out/renderer.
• The only /connect occurrences in the desktop renderer are inside error-message strings.

Request

Port the provider-connect flow to the desktop app — or minimally, a settings-panel section that writes the same auth.json / providers.json key store the CLI uses, so BYOK works identically across CLI and desktop. Right now a desktop-only user with their own API key is stuck.

Related: #954 (desktop model picker never lists BYOK providers from providers.json), #1016 (can't paste api-key for BYOK), #993 (ACP does not expose BYOK providers/models from providers.json)