PR #23176 runtime verification
GitCafe: https://git.cafe/pingdotgg/t3code/pulls/23193
main: 5732bbee39
PR: 1e428b679b978899428c13bf6de504fb326c6ffe
Linux, Node v24.22.1, real Chrome/Playwright, real Codex gpt-6.1-sol.
One background dev server at a time; isolated homes; no fixtures or mocks.

Scenario: create project for /home/user/verify-timeline through the web app.
Send real provider turn: cat README.md, pwd, git status.
Fork from completed response; send git log turn in fork.
Connect using server-issued MCP client credentials and call t3_thread_read.

BEFORE, github/main: real 8-item activity page.
limit=1: 1 item, 5 timeline statements, 1 per-item payload SELECT.
limit=50: 8 items, 12 timeline statements, 8 per-item payload SELECTs.
limit=100: 8 items, 12 timeline statements, 8 per-item payload SELECTs.
Counts taken from server sqlite spans under getTimelinePage, not a stand-in benchmark.

AFTER, exact PR head:
{"args":{"view":"activity","limit":1},"items":1,"hasMore":true,"nextPosition":0,"elapsedMs":13,"queries":5,"batchPayloads":1}
{"args":{"view":"activity","limit":50},"items":8,"hasMore":false,"nextPosition":7,"elapsedMs":12,"queries":5,"batchPayloads":1}
{"args":{"view":"activity","limit":100},"items":8,"hasMore":false,"nextPosition":7,"elapsedMs":20,"queries":5,"batchPayloads":1}
{"args":{"view":"messages","limit":100},"items":3,"hasMore":false,"nextPosition":6,"elapsedMs":15,"queries":5,"batchPayloads":1}
{"args":{"view":"activity","limit":2,"afterPosition":0},"items":2,"hasMore":true,"nextPosition":2,"elapsedMs":7,"queries":5,"batchPayloads":1}
{"args":{"view":"activity","limit":100,"afterPosition":100000},"items":0,"hasMore":false,"nextPosition":null,"elapsedMs":5,"queries":5,"batchPayloads":1}

FORK, 8 inherited + synthetic marker + 5 local = 14 items:
{"args":{"view":"activity","limit":1},"items":1,"hasMore":true,"nextPosition":0,"elapsedMs":159,"queries":9,"batchPayloads":1}
{"args":{"view":"activity","limit":50},"items":14,"hasMore":false,"nextPosition":13,"elapsedMs":37,"queries":9,"batchPayloads":1}
{"args":{"view":"activity","limit":100},"items":14,"hasMore":false,"nextPosition":13,"elapsedMs":9,"queries":9,"batchPayloads":1}
{"args":{"view":"messages","limit":100},"items":6,"hasMore":false,"nextPosition":12,"elapsedMs":6,"queries":9,"batchPayloads":1}
{"args":{"view":"activity","limit":2,"afterPosition":0},"items":2,"hasMore":true,"nextPosition":2,"elapsedMs":8,"queries":9,"batchPayloads":1}
{"args":{"view":"activity","limit":100,"afterPosition":100000},"items":0,"hasMore":false,"nextPosition":null,"elapsedMs":7,"queries":9,"batchPayloads":1}

PASS: root and fork message-only results equal the message subset of full activity.
PASS: every itemId returns exactly the same item as its full-page counterpart.
PASS: 3-item pages reconstruct the entire ordered history without omissions/duplicates.
PASS: inherited items preserve source thread identity; fork marker remains synthetic.
PASS: empty page returns no items, hasMore=false and nextPosition=null.
PASS: real provider invoked t3_thread_read through its own injected MCP configuration on both main and the exact PR head.
PASS: 37 focused existing tests on Blacksmith (ProjectionStore and MCP activity).
No timing speedup claim: elapsed values above are individual live requests on different revisions.
No source changes.