feat(evaluations): define performance levels

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/lib/evaluations/levels.ts

@@ -0,0 +1,51 @@
+/**
+ * Pure performance level definitions for leadership evaluations.
+ *
+ * This module has no Payload imports — it is safe to use from server actions,
+ * integration tests, and (later) frontend components. The UI renders these as
+ * bar/gradient displays; `score` drives the numeric aggregation and `color`
+ * the per-level accent.
+ */
+
+export interface PerformanceLevel {
+  /** Stable identifier stored on evaluation docs. */
+  id: string;
+  /** Human-readable label, e.g. shown as "OPERATOR PERFORMANCE LEVEL: EXCELLENT". */
+  label: string;
+  /** Numeric score (0–100) used for aggregate bar/percentage display. */
+  score: number;
+  /** Hex color for UI bars/gradients. */
+  color: string;
+}
+
+/**
+ * The performance scale, best to worst. At least five levels are required by the
+ * leadership-evaluations feature; six are defined so the top of the scale has room
+ * above "EXCELLENT" without collapsing distinctions.
+ */
+export const PERFORMANCE_LEVELS = [
+  { id: "exceptional", label: "EXCEPTIONAL", score: 100, color: "#34d399" },
+  { id: "excellent", label: "EXCELLENT", score: 85, color: "#4ade80" },
+  { id: "proficient", label: "PROFICIENT", score: 70, color: "#a3e635" },
+  { id: "adequate", label: "ADEQUATE", score: 55, color: "#fbbf24" },
+  { id: "moderate", label: "MODERATE", score: 40, color: "#94a3b8" },
+  { id: "under-review", label: "UNDER REVIEW", score: 25, color: "#f87171" },
+] as const satisfies readonly PerformanceLevel[];
+
+export type PerformanceLevelId = (typeof PERFORMANCE_LEVELS)[number]["id"];
+
+const LEVEL_IDS: ReadonlySet<string> = new Set(PERFORMANCE_LEVELS.map((l) => l.id));
+
+/** Type guard for runtime-validated level ids (DB/API input). */
+export function isPerformanceLevelId(value: unknown): value is PerformanceLevelId {
+  return typeof value === "string" && LEVEL_IDS.has(value);
+}
+
+/** Resolve a level definition by id, or null when unknown. */
+export function getPerformanceLevel(id: string): PerformanceLevel | null {
+  return PERFORMANCE_LEVELS.find((l) => l.id === id) ?? null;
+}
+
+export function getLeadershipDisplayLabel(level: Pick<PerformanceLevel, "id" | "label">): string {
+  return level.id === "under-review" ? "NEEDS WORK" : level.label;
+}