pub fn resolve_shared_registry_dir() -> Option<PathBuf>Expand description
Resolve the GLOBAL <home>/shared/agents/registry/ directory.
P0.3 re-roots the named-instance registry from the old
channel-scoped channels/<ch>/agents/registry/ (which walked
AGENTMUX_DATA_DIR up three levels and so landed inside the current
channel) to the channel-independent ~/.agentmux/shared/. An agent
named in one channel is then visible in every channel, exactly like the
definition store (resolve_shared_definitions_dir) — the two are now
siblings under shared/agents/.
The base directory that instance working_directory values are stored
relative to is tracked separately (the Store’s registry_agents_base,
fed from AGENTMUX_AGENTS_DIR) — it must stay the current channel’s
agents dir even though the registry files are now global.
Returns None only if the global shared root can’t be resolved — caller
treats this as “registry disabled,” no write attempts.