1. _profile_default_workspace() now checks terminal.cwd
Profile config.yaml files don't have a 'workspace' or 'default_workspace' key
— they store the working directory as terminal.cwd (the hermes-agent CLI
setting). Added it as the third fallback after 'workspace' and
'default_workspace', so switching to camanji correctly resolves
~/Camanji, webui resolves ~/webui-mvp, etc.
2. Workspace dropdown opens upward (bottom: calc(100% + 4px))
The dropdown is now anchored at the bottom of the sidebar. Opening it
downward (top: 100%) caused it to clip off screen. Flipped to open upward
with an upward shadow so it expands into the session list area instead.
Tests: 426 passed, 0 failed.
3d8cf85ef2