Fix PR coverage comment posting in CI.

Build the Gitea API payload with json.dumps so multiline coverage output is valid JSON, and fail the step when the API rejects the request.

Co-authored-by: Cursor <cursoragent@cursor.com>

.gitea/workflows/test.yml

@@ -40,9 +40,20 @@ jobs:
           PR_NUMBER: ${{ github.event.pull_request.number }}
           CI_RUNNER_TOKEN: ${{ secrets.CI_RUNNER_TOKEN }}
         run: |
-          COVERAGE=$(cat coverage.txt)
-          COMMENT_BODY="**Test Coverage Report:**\n\`\`\`\n$COVERAGE\n\`\`\`"
-          curl -s -X POST "$API_URL/repos/$REPO_OWNER/$REPO_NAME/issues/$PR_NUMBER/comments" \
+          PAYLOAD=$(python3 -c '
+          import json
+          import pathlib
+
+          coverage = pathlib.Path("coverage.txt").read_text()
+          print(
+              json.dumps(
+                  {
+                      "body": f"**Test Coverage Report:**\n```\n{coverage}\n```",
+                  }
+              )
+          )
+          ')
+          curl -sf -X POST "$API_URL/repos/$REPO_OWNER/$REPO_NAME/issues/$PR_NUMBER/comments" \
             -H "Authorization: token $CI_RUNNER_TOKEN" \
             -H "Content-Type: application/json" \
-            -d "{\"body\": \"$COMMENT_BODY\"}"
+            -d "$PAYLOAD"