Recent sessions disappeared from the list when opencode serve was launched
outside $HOME (e.g. ~/workspace/opencode). The list path scoped to
server.home, but opencode-server resolves x-opencode-directory to a project
id by exact-match, not subtree prefix. $HOME mapped to the synthetic
'global' project, which never contained the user's workspace sessions.
Change the single-source-of-truth rule to return null (no scope header) when
the connection has no explicit directory. The server then uses its own CWD
project — the same project sessions are actually created in. Both list and
create paths still derive from sessionScopeDirectory, so #10's drift cure is
preserved.
Verified against 100.108.64.76:4096: no header returns the recent workspace
sessions (Opencode npm install, autopilot_exit, ...); header=$HOME returns
only the empty global project.
Closes#32
79d26f0fbd