Add roster-tuner skill: agency roster performance tuning

[tttt28444]

Summary

Adds the skill to the runx catalog.

This skill reads a sealed agency case event stream through the hosted data-store, folds per-member metrics (turn count, refusal tally, completion time), ranks members against operator-supplied norms, and emits a typed roster tuning decision naming the bounded member change as plain data.

What it does

• Reads case projection via ()
• Folds per-member metrics: turn count, refusal rate, avg completion time
• Grades each member against operator norms (refusal_threshold, completion_time_threshold)
• Enforces guard rails: min_roster_size, sole_skill protection, schema version match
• Appends judgment as ungated CAS write to the case event stream
• Emits decision packet; never executes a roster mutation

Harness cases

• : member at refusal_rate 0.75 above 0.6 threshold and completion_time 3x norm, yields underperformer verdict with skill-matched replacement
• : caller.answers omitted, grading agent-task blocks, run stops with needs_agent before any decision is appended

Files

• skills/roster-tuner/X.yaml - skill definition with typed inputs/outputs and graph runner
• skills/roster-tuner/SKILL.md - human/agent-readable skill documentation
• skills/roster-tuner/fixtures/ - harness test case fixtures
• skills/roster-tuner/graph/ - sub-graph implementations (fold, grade, decide)

Usage