feat: enforce agent icon enum and expose via LLM endpoint

Move icon name list to shared constants with strict enum validation.
Add /llms/agent-icons.txt endpoint, pass icon through hire flow,
and update skills to reference icon discovery step.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/shared/src/constants.ts

@@ -39,6 +39,51 @@ export const AGENT_ROLES = [
 ] as const;
 export type AgentRole = (typeof AGENT_ROLES)[number];
 
+export const AGENT_ICON_NAMES = [
+  "bot",
+  "cpu",
+  "brain",
+  "zap",
+  "rocket",
+  "code",
+  "terminal",
+  "shield",
+  "eye",
+  "search",
+  "wrench",
+  "hammer",
+  "lightbulb",
+  "sparkles",
+  "star",
+  "heart",
+  "flame",
+  "bug",
+  "cog",
+  "database",
+  "globe",
+  "lock",
+  "mail",
+  "message-square",
+  "file-code",
+  "git-branch",
+  "package",
+  "puzzle",
+  "target",
+  "wand",
+  "atom",
+  "circuit-board",
+  "radar",
+  "swords",
+  "telescope",
+  "microscope",
+  "crown",
+  "gem",
+  "hexagon",
+  "pentagon",
+  "fingerprint",
+] as const;
+export type AgentIconName = (typeof AGENT_ICON_NAMES)[number];
+
 export const ISSUE_STATUSES = [
   "backlog",
   "todo",