fix(cli): drop misleading FLAGS section from root --help

The hand-written FLAGS block in `lark-cli --help` listed --params,
--data, --as, --format, --page-all, --page-size, --page-limit,
--page-delay, -o, --jq, -q and --dry-run as if they were global flags.
None are registered on the root command — they all error "unknown flag"
at the top level and exist only on leaf commands (api, service). The
block also contradicted the Cobra-generated "Flags:" section rendered
directly below it, which shows only -h/--help, --profile, -v/--version.

Remove the static cheat-sheet so Cobra's real per-command flag output is
the single source of truth and the two sections can no longer drift.
USAGE/EXAMPLES still show these flags in their correct position (after a
command), which remains accurate.

Change-Id: Ib801608d2cba8a759c12fa151af62fab707fb023

Author: liangshuo-1

cmd/root.go

@@ -48,20 +48,6 @@ EXAMPLES:
     # Generic API call
     lark-cli api GET /open-apis/calendar/v4/calendars
 
-FLAGS:
-    --params <json>       URL/query parameters JSON
-    --data <json>         request body JSON (POST/PATCH/PUT/DELETE)
-    --as <type>           identity type: user | bot
-    --format <fmt>        output format: json (default) | ndjson | table | csv | pretty
-    --page-all            automatically paginate through all pages
-    --page-size <N>       page size (0 = use API default)
-    --page-limit <N>      max pages to fetch with --page-all (default: 10, 0 for unlimited)
-    --page-delay <MS>     delay in ms between pages (default: 200, only with --page-all)
-    -o, --output <path>   output file path for binary responses
-    --jq <expr>           jq expression to filter JSON output
-    -q <expr>             shorthand for --jq
-    --dry-run             print request without executing
-
 AI AGENT SKILLS:
     lark-cli pairs with AI agent skills (Claude Code, etc.) that
     teach the agent Lark API patterns, best practices, and workflows.