Issue 900

# CLIProxy Control Panel Embed Fix

Before the fix, the embedded upstream management center landed on `#/login` and asked for credentials again. After the fix, the same surface boots straight into the authenticated dashboard and starts reading `/api/cliproxy-local/v0/management/*`.

## Embedded Control Panel

Captures use the same route and light theme. The colored callout box marks the iframe review area.

Before: iframe falls back to login
After: iframe opens management dashboard

Broken state: iframe URL ended at `/management.html#/login`.

Fixed state: iframe URL ends at `/management.html#/`.

Fixed build verified live against the patched worktree dashboard on `localhost:3001`.