CLI subcommand tree via decline

[Sootopolis]

Depends on

• Packaging (Main entry exists) — #41

Blocks

• ccas serve lifecycle — #48
• Shell completions (consume the decline command tree) — #49

What

Add decline (com.monovore::decline-effect) and build the subcommand tree.

Public subcommands

Subcommand	Maps to
ccas serve	boots CcasServer (foreground)
ccas membership <slug> [...]	POST /api/jobs/membership
ccas history <slugs...> [...]	POST /api/jobs/history
ccas recruit <slug> [...]	POST /api/jobs/recruitment
ccas stats <slug> [...]	POST /api/jobs/stats
ccas blacklist {add|list|remove} <slug>	BlacklistRoutes
ccas schedule {list|add|remove}	ScheduleRoutes
ccas logs <job_id>	GET /api/jobs/{id}/logs live tail
ccas jobs [...]	GET /api/jobs listings
ccas __complete <args>	hidden; returns completion matches

Hidden admin subcommands (decline Visibility.Partial)

Subcommand	Maps to
ccas admin ref [--force]	POST /api/admin/jobs/matchref
ccas admin clubdata [--force] [<slug>...]	POST /api/admin/jobs/clubdata

Per #50 (closed 2026-05-27): MatchRef and ClubData are server-internal — no public subcommand, no --help listing. Hidden admin escape hatch for ops debugging only. Default JobSchedule rows (see #45) cover the normal cadence.

History stays public because users do want explicit "ingest this club's matches now" semantics (esp. first-seed). Default JobSchedule for History keeps steady state warm.

Each subcommand serializes the same case classes (MembershipRequest, HistoryRequest, ...) that JobRoutes already accepts. HTTP client uses HttpClientLayer.live for consistency.

After a successful submit, poll GET /api/jobs/{id} until terminal, streaming logs from GET /api/jobs/{id}/logs once the file-tail endpoint lands; until then just poll status.

Acceptance

• All listed public subcommands parse via decline and produce a usable --help per subcommand.
• Hidden ccas admin ref / ccas admin clubdata work but do not appear in ccas --help output.
• ccas membership team-alpha against a running local server returns exit 0 on success, non-zero on job failure, with the server-side error message printed.
• ccas <invalid> exits non-zero with the standard decline "unknown command" suggestion.

Files

• build.sbt — add decline-effect.
• new src/main/scala/ccas/cli/ — command tree, HTTP client, poll loop.
• src/main/scala/ccas/cli/Main.scala — dispatch into the command tree.

Reference

Tracked under epic #40 (CLI v0). Outcome of #50 decision (closed 2026-05-27).