Custom session storage directories
- Dashboard now honors the global
sessionDir for Fleet, session inventory, resync, resume, and deletion, while preventing project settings from redirecting host-wide inventory.
- Added global-only
subagentSessionDir configuration for single, parallel, and chain subagent transcripts.
- RPC session listing and restart recovery now use the effective configured roots, with configured-first discovery and backward-compatible recovery from the legacy subagent directory.
- Custom main-session stores retain flat-directory semantics; default installations keep the existing nested all-project inventory.
- Absolute, tilde-prefixed, and relative paths now use shared documented resolution rules across CLI, RPC, Dashboard, and subagent runtimes.
- Operational storage failures surface explicitly instead of appearing as an empty or incomplete inventory; existing files are not migrated.
- Updated public documentation and comprehensive configuration, inventory, recovery, RPC, and Dashboard regression coverage.
Implemented in PR 522, resolving issue 509.
