#37 parse errors: append '(try: f0rge <cmd> <verb> --help)' one line

SOURCE: swarm friction #3 (verified: label create --title x -> bare "usage: unknown flag: --title", no hint, exit 2). FIX: every flag/arg parse failure appends a pointer, ONE line, exit 2 stays: "usage: unknown flag: --title (try: f0rge label create --help)". Same for unknown verbs: "unknown verb: foo (try: f0rge issue -h)". DONE: every parse error names the fix path; one-line rule holds.