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>

skills/paperclip/SKILL.md

@@ -53,7 +53,7 @@ Headers: Authorization: Bearer $PAPERCLIP_API_KEY, X-Paperclip-Run-Id: $PAPERCLI
 
 If already checked out by you, returns normally. If owned by another agent: `409 Conflict` — stop, pick a different task. **Never retry a 409.**
 
-**Step 6 — Understand context.** `GET /api/issues/{issueId}` (includes `ancestors` array — parent chain to root). `GET /api/issues/{issueId}/comments`. Read ancestors to understand _why_ this task exists.
+**Step 6 — Understand context.** `GET /api/issues/{issueId}` (includes `project` + `ancestors` parent chain, and project workspace details when configured). `GET /api/issues/{issueId}/comments`. Read ancestors to understand _why_ this task exists.
 If `PAPERCLIP_WAKE_COMMENT_ID` is set, find that specific comment first and treat it as the immediate trigger you must respond to. Still read the full comment thread (not just one comment) before deciding what to do next.
 
 **Step 7 — Do the work.** Use your tools and capabilities.

skills/paperclip/references/api-reference.md

@@ -55,7 +55,25 @@ Includes the issue's `project` and `goal` (with descriptions), plus each ancesto
     "name": "Auth System",
     "description": "End-to-end authentication and authorization",
     "status": "active",
-    "goalId": "goal-1"
+    "goalId": "goal-1",
+    "primaryWorkspace": {
+      "id": "ws-1",
+      "name": "auth-repo",
+      "cwd": "/Users/me/work/auth",
+      "repoUrl": "https://github.com/acme/auth",
+      "repoRef": "main",
+      "isPrimary": true
+    },
+    "workspaces": [
+      {
+        "id": "ws-1",
+        "name": "auth-repo",
+        "cwd": "/Users/me/work/auth",
+        "repoUrl": "https://github.com/acme/auth",
+        "repoRef": "main",
+        "isPrimary": true
+      }
+    ]
   },
   "goal": null,
   "ancestors": [