queen: route each task to the cheapest tier that can finish it, and escalate one tier on send-back #9972

Part of the dispatch roadmap epic #9976. Industry reference and the measured gap are below.

Every bee dispatch today uses the same agent setup regardless of the task. A port task (one Python file to one .t27) and compiler work cost the same, and a send-back retries with the setup that just failed.

Industry reference: FrugalGPT and RouteLLM cascades (cheap model first, escalate on low confidence) report large cost cuts at equal quality; production agent schedulers route by task class.

User Scenarios

• As the Queen, I send a small port task to the fast tier and a compiler task to the strongest tier.
• As the Queen, when a task comes back with a send-back, the retry goes one tier up instead of repeating the same attempt.

Requirements

• task_class(domain, boundary_paths, est_lines) -> u8, tier_for(task_class, send_backs) -> u8, the tier ladder as named constants.
• The top tier is used only after a send-back or for named classes.
• The card names tiers, not vendors or prices.

Success Criteria

• Tests: each class lands on its tier; every send-back moves exactly one tier up and never past the top.
• Invariant: tier is monotonic in send-backs.
• 0 surviving mutants.

Rules for the bee

• Only .t27 is hand-written; the seal is tool-written (t27c seal --save after a fresh release build on the Railway lab). No .py, .rs, .ts, .sh or .yml edits.
• Every rule gets test blocks and at least one invariant; run tri mutate spec on the new file (on the lab) and kill every surviving mutant. The bar is specs/queen/dispatch.t27 in PR test(queen): kill the 39 surviving mutants of specs/queen/dispatch.t27 #9961: 0 survivors, 0 vacuous tests.
• Write the measured numbers that motivate the card into its header comment, as specs/queen/holds.t27 does.
• Wiring into the runtime (gHashTag/trios) is a separate step: it lands as generated code once gen-ts lowers pure function bodies (gen-ts: lower the bodies of pure functions, so a host imports a spec's rule instead of copying it #7871 / PR gen-ts: lower the bodies of pure functions #7872). Do not hand-write TypeScript here.

Boundary

• specs/queen/routing.t27
• .trinity/seals/queen_QueenRouting.json