Move artifact upload guidance into Paperclip skill

Co-Authored-By: Paperclip <noreply@paperclip.ing>

skills/paperclip/SKILL.md

@@ -94,6 +94,51 @@ If `currentParticipant` does not match you, do not try to advance the stage —
 - If blocked, move the issue to `blocked` with the unblock owner and exact action needed.
 - Respect budget, pause/cancel, approval gates, execution policy stages, and company boundaries.
 
+### Generated Artifacts and Work Products
+
+When work produces a user-inspectable file, upload it to the current issue before final disposition. Local filesystem paths are not enough because board users, reviewers, and cloud operators may not have access to the agent workspace.
+
+Use the repo helper when it exists in the active workspace:
+
+```bash
+scripts/paperclip-upload-artifact.sh path/to/output.webm \
+  --title "Walkthrough render" \
+  --summary "Rendered walkthrough for review"
+```
+
+The helper uses `PAPERCLIP_API_URL`, `PAPERCLIP_API_KEY`, `PAPERCLIP_COMPANY_ID`, `PAPERCLIP_TASK_ID`, and `PAPERCLIP_RUN_ID`. It uploads the file as an issue attachment, creates an attachment-backed artifact work product by default, and prints issue-safe markdown links for your final comment.
+
+If the helper is unavailable, use the Paperclip API directly:
+
+```bash
+curl -sS -X POST \
+  "$PAPERCLIP_API_URL/api/companies/$PAPERCLIP_COMPANY_ID/issues/$PAPERCLIP_TASK_ID/attachments" \
+  -H "Authorization: Bearer $PAPERCLIP_API_KEY" \
+  -H "X-Paperclip-Run-Id: $PAPERCLIP_RUN_ID" \
+  -F 'file=@"path/to/output.webm";type=video/webm'
+```
+
+Then create a work product when the file is the deliverable. The server canonicalizes attachment-backed artifact metadata from the `attachmentId`:
+
+```bash
+curl -sS -X POST \
+  "$PAPERCLIP_API_URL/api/issues/$PAPERCLIP_TASK_ID/work-products" \
+  -H "Authorization: Bearer $PAPERCLIP_API_KEY" \
+  -H "X-Paperclip-Run-Id: $PAPERCLIP_RUN_ID" \
+  -H "Content-Type: application/json" \
+  --data-binary '{
+    "type": "artifact",
+    "provider": "paperclip",
+    "title": "Walkthrough render",
+    "status": "ready_for_review",
+    "reviewState": "needs_board_review",
+    "isPrimary": true,
+    "metadata": { "attachmentId": "<uploaded-attachment-id>" }
+  }'
+```
+
+In your final issue comment, link the uploaded attachment or work product and describe what it contains. Do not leave artifact-producing work `in_progress` with only a local path or a `Remaining` note.
+
 **Step 8 — Update status and communicate.** Always include the run ID header.
 If you are blocked at any point, you MUST update the issue to `blocked` before exiting the heartbeat, with a comment that explains the blocker and who needs to act.