wip: pull request view & md rendering

fixtures/github/issues.pull_request_timeline.PR_kwDODesign31.page1.json

@@ -0,0 +1,66 @@
+{
+  "node": {
+    "__typename": "PullRequest",
+    "timelineItems": {
+      "pageInfo": {
+        "endCursor": "timeline:PR_kwDODesign31:page1",
+        "hasNextPage": false
+      },
+      "nodes": [
+        {
+          "__typename": "AssignedEvent",
+          "createdAt": "2026-05-02T11:12:00Z",
+          "actor": {
+            "__typename": "User",
+            "login": "mariahops",
+            "avatarUrl": "https://avatars.githubusercontent.com/u/6161?v=4"
+          },
+          "assignee": {
+            "__typename": "User",
+            "login": "kennethnym",
+            "avatarUrl": "https://avatars.githubusercontent.com/u/4242?v=4"
+          }
+        },
+        {
+          "__typename": "PullRequestReview",
+          "createdAt": "2026-05-02T15:40:00Z",
+          "author": {
+            "__typename": "User",
+            "login": "kennethnym",
+            "avatarUrl": "https://avatars.githubusercontent.com/u/4242?v=4"
+          },
+          "state": "CHANGES_REQUESTED",
+          "body": "The 12px sidebar gutter still feels cramped."
+        },
+        {
+          "__typename": "BaseRefChangedEvent",
+          "createdAt": "2026-05-02T18:05:00Z",
+          "actor": {
+            "__typename": "User",
+            "login": "mariahops",
+            "avatarUrl": "https://avatars.githubusercontent.com/u/6161?v=4"
+          }
+        },
+        {
+          "__typename": "IssueComment",
+          "createdAt": "2026-05-02T18:18:00Z",
+          "author": {
+            "__typename": "User",
+            "login": "mariahops",
+            "avatarUrl": "https://avatars.githubusercontent.com/u/6161?v=4"
+          },
+          "body": "Updated the spacing tokens to align with the latest mock."
+        },
+        {
+          "__typename": "AutoMergeEnabledEvent",
+          "createdAt": "2026-05-03T09:00:00Z",
+          "actor": {
+            "__typename": "User",
+            "login": "kennethnym",
+            "avatarUrl": "https://avatars.githubusercontent.com/u/4242?v=4"
+          }
+        }
+      ]
+    }
+  }
+}