refactor(cli): split cli-dispatch.ts into group dispatchers + usage module
- cli-dispatch.ts: 775 → 149 lines (top-level routing only)
- cli-usage.ts: usage formatting (formatCliUsage, formatUsageCommandLines)
- cli-command-types.ts: shared types (DispatchFn, CommandEntry, CommandGroup)
- cli-registry.ts: getCommandRegistry() assembling all group tables
- cli-usage-context.ts: decouple usage from registry (avoids circular deps)
- commands/{workflow,thread,cas,init}/dispatch.ts: group-specific dispatch
functions + subcommand tables
- 242 tests pass, CLI output identical, biome clean
Refs #96
xingyue
6a99f84025