The /resume usage hint shows '<session_id_or_title>' which a few users have
typed verbatim, including the angle brackets. Strip outer <>, [], "", and ''
from the argument before lookup so '/resume <abc123>' works the same as
'/resume abc123'. Mirrors the new bracket-stripping in the CLI handler.
Also let the gateway resolve a bare session ID. Previously the gateway only
called resolve_session_by_title, so '/resume <session_id>' always returned
'Session not found' even for valid IDs. Try get_session() first, fall back
to title resolution second.
Surgical reapply of PR #10215 (branch was based on a many-months-old main
and reverted ~3100 unrelated files; original commit by claw@openclaw.ai
preserved via --author).