When a user runs `hermes -w -c Pokemon Agent Dev` without quoting the
session name, argparse would fail with:
error: argument command: invalid choice: 'Agent'
This is because argparse parses `-c Pokemon` (consuming one token via
nargs='?'), then sees 'Agent' and tries to match it as a subcommand.
Fix: add _coalesce_session_name_args() that pre-processes sys.argv before
argparse, joining consecutive non-flag, non-subcommand tokens after -c or
-r into a single argument. This makes both quoted and unquoted multi-word
session names work transparently.
Includes 17 tests covering all edge cases: multi-word names, single-word,
bare flags, flag ordering, subcommand boundaries, and passthrough.