feat(config): add configurable agent ordering

src/shared/agent-ordering.ts

@@ -0,0 +1,61 @@
+import { AGENT_DISPLAY_NAMES, getAgentConfigKey, getAgentListDisplayName } from "./agent-display-names"
+
+export const DEFAULT_AGENT_ORDER = [
+  "sisyphus",
+  "hephaestus",
+  "prometheus",
+  "atlas",
+] as const
+
+export type AgentOrderValidation = {
+  order: string[]
+  invalid: string[]
+  duplicates: string[]
+}
+
+const KNOWN_AGENT_KEYS = new Set(Object.keys(AGENT_DISPLAY_NAMES))
+
+function appendUnique(target: string[], value: string): void {
+  if (!target.includes(value)) {
+    target.push(value)
+  }
+}
+
+export function validateAgentOrder(agentOrder: readonly string[] | undefined): AgentOrderValidation {
+  const order: string[] = []
+  const invalid: string[] = []
+  const duplicates: string[] = []
+  const seen = new Set<string>()
+
+  for (const rawName of agentOrder ?? []) {
+    const trimmed = rawName.trim()
+    if (trimmed.length === 0) {
+      invalid.push(rawName)
+      continue
+    }
+
+    const configKey = getAgentConfigKey(trimmed)
+    if (!KNOWN_AGENT_KEYS.has(configKey)) {
+      invalid.push(rawName)
+      continue
+    }
+
+    if (seen.has(configKey)) {
+      duplicates.push(rawName)
+      continue
+    }
+
+    seen.add(configKey)
+    order.push(configKey)
+  }
+
+  for (const configKey of DEFAULT_AGENT_ORDER) {
+    appendUnique(order, configKey)
+  }
+
+  return { order, invalid, duplicates }
+}
+
+export function resolveAgentOrderDisplayNames(agentOrder: readonly string[] | undefined): string[] {
+  return validateAgentOrder(agentOrder).order.map((configKey) => getAgentListDisplayName(configKey))
+}