Wire flagspec_render_help() into cmd_help via new command_t fields
(flagspec/flagspec_count/usage_tail), so every flag-accepting command's
help composes description -> generated flag block -> example/related
notes, with hand-written per-flag lines removed as a duplicate source of
truth. Add missing purpose descriptions, examples, and confirmation-gate
related notes across ~20 commands; fix bug-1711's "matchs" grammar
(Req 11.2); confirm join's corrected maxmem default (bug-1557, Req 12.2)
and the --json flag (Req 5.4) now render correctly end-to-end.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019jaMf9QEwpugH2W9KAuc7f
Rongsong Shen
96746af3eb