[SELF-SPEC-01] Arm Performance Leaderboard — retrospective-powered component

## SELF-GENERATED SPEC — Created by Foundry Retrospective System This spec was auto-generated from retrospective analysis identifying a gap: "No visibility into arm × asset-type performance trends over time." ### User Story As a Foundry operator, I want to see a leaderboard of arm (AI model) performance broken down by task type, showing pass rate, average quality, cost efficiency, and trend direction, so I can validate that routing overrides from the retrospective are working. ### Target File: `foundry-dashboard/src/components/arm-leaderboard.tsx` (NEW) Integration: Import in `foundry-dashboard/src/components/foundry-control-plane.tsx` ### Tech Stack (match existing codebase) - Next.js 16 + React 19 + Tailwind 4 - Server-side Supabase data fetching (service role key, never client-side) - Dark mode first, monospace aesthetic (Geist Mono) - Card-based layout with `rounded-lg border border-border bg-card` ### Component Spec ```typescript interface ArmLeaderboardProps { arms: Array<{ name: string; // e.g. "G3 Flash", "Sonnet 4", "Opus 4.5" task_types: Record<string, { count: number; pass_rate: number; // 0-1 avg_quality: number; // 0-1 avg_cost: number; // USD }>; overall_pass_rate: number; overall_quality: number; total_tasks: number; total_cost: number; }>; } ``` ### Visual Layout 1. **Leaderboard table** sorted by overall_quality descending 2. Each row: Rank medal (gold/silver/bronze), Arm name, Total tasks, Pass rate (color-coded bar), Avg quality, Total cost 3. **Expandable row detail**: breakdown by task_type with mini bar charts 4. **Color coding**: pass_rate >= 0.8 green, >= 0.6 yellow, < 0.6 red 5. **Cost efficiency badge**: quality_per_dollar = avg_quality / avg_cost (higher = better) ### Data Source Query `foundry_tasks` WHERE status = 'completed' AND quality IS NOT NULL, GROUP BY claimed_by, task_type. Add to existing `fetchControlPlaneData()` in `foundry-dashboard/src/lib/supabase.ts`. ### Acceptance Criteria (Grader Tests) - File `foundry-dashboard/src/components/arm-leaderboard.tsx` must exist - Must contain `interface ArmLeaderboardProps` or `type ArmLeaderboardProps` - Must contain `pass_rate` (at least 2 occurrences — display + color logic) - Must contain `avg_quality` (at least 1 occurrence) - Must contain `task_type` or `task_types` (at least 1 occurrence) - Must contain `bg-card` or `border-border` (Tailwind dark-mode pattern) - Must contain `export` (component is exported) - Must NOT contain `createClient` (no client-side Supabase — data comes via props) - File must be valid TypeScript/TSX (no syntax errors)