fix(models): coding runs on sonnet-5, judging on opus-5, haiku only as last resort

Operator model policy: haiku ONLY for genuine yes/no questions; anything
requiring thinking is opus-5; coding is sonnet-5.

The mission AGENTS were running haiku, and nothing in the product said so.
`provider_alias_for` maps every `claude-*` binding onto the single alias
`claude_cli.default`, so a crew whose `model_binding` reads `claude-sonnet-5`
— as this deployment's does — still ran whatever that alias pointed at, which
was `model = "haiku"` in the runtime config. The binding is cosmetic; the
alias is the truth.

Measured consequence on mission 01a00bbb: the coding agents claimed six INT
items complete and had committed three, and the done_when judge caught it by
auditing git history against the claims.

Model assignments, by what the component actually does:
  evaluator (done_when judge)  haiku  -> opus-5   reads evidence, audits it
                                                  against the repo, writes
                                                  guidance. The verdict is a
                                                  boolean; the work is not —
                                                  and this is the one component
                                                  whose failure mode is passing
                                                  work that was never done.
  judge_model                  4-8    -> opus-5
  mission_refiner              4-8    -> opus-5   composition
  phase_summarizer             4-8    -> opus-5   composition
  swarm planner                4-8    -> opus-5   planning
  subscription preflight head  4-8    -> opus-5
  fallback chain head          4-6    -> sonnet-5 haiku stays BELOW it as a
                                                  last-resort link, never a peer

Every value stays env-overridable; only the shipped defaults move.

Co-Authored-By: Claude Opus 5 <[email protected]>

crates/cm-api/src/mission_refiner.rs

@@ -13,7 +13,7 @@
 use sqlx::PgPool;
 use uuid::Uuid;
 
-const DEFAULT_MODEL: &str = "claude-opus-4-8";
+const DEFAULT_MODEL: &str = "claude-opus-5";
 
 fn model_name() -> String {
     std::env::var("CLAWMATES_REFINER_MODEL").unwrap_or_else(|_| DEFAULT_MODEL.to_string())