Real development verification, PR 28265
Main: 54c5f25249 (github/main at verification)
PR: e25e063cdc8ae518afcd3e2532848c5d17da5cff
Chrome: /usr/bin/google-chrome; Playwright 1.60.0 from repository dependencies.
Data: project /home/user/fork-verification, created through web UI; real git repository. Threads and all turn data created through app. No fixtures, mocks, replay, or seeded data.
Provider: Codex gpt-6.1-sol through local proxy.
Only one dev server ran at a time. Main PID 16788 stopped before PR PID 24985 started.

Main reproduction: dispatch.threadFork latest_stable reads checkpoints once and context_transfers once. Existing server trace, descendants of the fork dispatch span, no code instrumentation.
PR: latest_stable and run source forks read neither table. Explicit checkpoint fork reads checkpoints once and context_transfers zero times.
Counts below include the target existence query as well as source projection reads; no end-to-end speed claim.

Real-client behavior on main and PR:
1. Parent prompt stores cedar lantern; real Codex replies cedar lantern ready.
2. /side opens side chat; approve real t3_thread_read request; Codex recalls cedar lantern.
3. Side prompt includes side-only code amber otter. Bring back then next parent prompt recalls amber otter.
Additional PR neighbors:
4. Fork from first response through UI; new thread shows selected history, next Codex turn recalls cedar lantern.
5. Explicit checkpoint thread.fork through authenticated WebSocket, using actual checkpoint captured by first real turn. forkedFrom resolves to first source run. Open resulting thread in UI; next Codex turn recalls cedar lantern.

Blacksmith:
vp test run apps/server/src/orchestration-v2/ThreadFork.execution.test.ts: 11/11 pass.
vp run check:changed 15fe2832727893cbdd2214383f9f971474849695: format, lint, both knip passes, GraphQL, affected typechecks, 27/27 tests pass.
Runner required depth-2 fetch of contributor branch because its initial snapshot was shallow at HEAD.

Unverified: native desktop/mobile, other providers, relay/tunnel, very large parent histories, end-to-end latency improvement.
No code changes, commits, pushes, labels, merges, rebases, or force pushes.

MAIN FORK TRACE
{
  "source": "latest_stable",
  "exit": {
    "_tag": "Success"
  },
  "queries": [
    "SELECT payload_json FROM orchestration_v2_projection_threads WHERE thread_id = ? LIMIT 1",
    "SELECT payload_json FROM orchestration_v2_projection_runs WHERE thread_id = ? ORDER BY ordinal ASC",
    "SELECT payload_json FROM orchestration_v2_projection_run_attempts WHERE thread_id = ? ORDER BY run_id ASC, attempt_ordinal ASC",
    "SELECT payload_json FROM orchestration_v2_projection_provider_threads WHERE thread_id = ? OR owner_node_id IN ( SELECT node_id …[truncated]",
    "SELECT payload_json FROM orchestration_v2_projection_provider_turns WHERE thread_id = ? ORDER BY provider_thread_id ASC, ordinal ASC",
    "SELECT payload_json FROM orchestration_v2_projection_checkpoints WHERE thread_id = ? ORDER BY scope_id ASC, ordinal_within_scope ASC",
    "SELECT payload_json FROM orchestration_v2_projection_context_transfers WHERE source_thread_id = ? OR target_thread_id = ? ORDER BY rowid ASC",
    "SELECT payload_json FROM orchestration_v2_projection_threads WHERE thread_id = ?"
  ],
  "checkpointReads": 1,
  "contextTransferReads": 1
}

PR FORK TRACES
{
  "source": "latest_stable",
  "exit": {
    "_tag": "Success"
  },
  "queries": [
    "SELECT payload_json FROM orchestration_v2_projection_threads WHERE thread_id = ? LIMIT 1",
    "SELECT payload_json FROM orchestration_v2_projection_runs WHERE thread_id = ? ORDER BY ordinal ASC",
    "SELECT payload_json FROM orchestration_v2_projection_run_attempts WHERE thread_id = ? ORDER BY run_id ASC, attempt_ordinal ASC",
    "SELECT payload_json FROM orchestration_v2_projection_provider_threads WHERE thread_id = ? OR owner_node_id IN ( SELECT node_id …[truncated]",
    "SELECT payload_json FROM orchestration_v2_projection_provider_turns WHERE thread_id = ? ORDER BY provider_thread_id ASC, ordinal ASC",
    "SELECT payload_json FROM orchestration_v2_projection_threads WHERE thread_id = ?"
  ],
  "checkpointReads": 0,
  "contextTransferReads": 0
}
{
  "source": "run",
  "exit": {
    "_tag": "Success"
  },
  "queries": [
    "SELECT payload_json FROM orchestration_v2_projection_threads WHERE thread_id = ? LIMIT 1",
    "SELECT payload_json FROM orchestration_v2_projection_runs WHERE thread_id = ? ORDER BY ordinal ASC",
    "SELECT payload_json FROM orchestration_v2_projection_run_attempts WHERE thread_id = ? ORDER BY run_id ASC, attempt_ordinal ASC",
    "SELECT payload_json FROM orchestration_v2_projection_provider_threads WHERE thread_id = ? OR owner_node_id IN ( SELECT node_id …[truncated]",
    "SELECT payload_json FROM orchestration_v2_projection_provider_turns WHERE thread_id = ? ORDER BY provider_thread_id ASC, ordinal ASC",
    "SELECT payload_json FROM orchestration_v2_projection_threads WHERE thread_id = ?"
  ],
  "checkpointReads": 0,
  "contextTransferReads": 0
}
{
  "source": "checkpoint",
  "exit": {
    "_tag": "Success"
  },
  "queries": [
    "SELECT payload_json FROM orchestration_v2_projection_threads WHERE thread_id = ? LIMIT 1",
    "SELECT payload_json FROM orchestration_v2_projection_runs WHERE thread_id = ? ORDER BY ordinal ASC",
    "SELECT payload_json FROM orchestration_v2_projection_run_attempts WHERE thread_id = ? ORDER BY run_id ASC, attempt_ordinal ASC",
    "SELECT payload_json FROM orchestration_v2_projection_provider_threads WHERE thread_id = ? OR owner_node_id IN ( SELECT node_id …[truncated]",
    "SELECT payload_json FROM orchestration_v2_projection_provider_turns WHERE thread_id = ? ORDER BY provider_thread_id ASC, ordinal ASC",
    "SELECT payload_json FROM orchestration_v2_projection_checkpoints WHERE thread_id = ? ORDER BY scope_id ASC, ordinal_within_scope ASC",
    "SELECT payload_json FROM orchestration_v2_projection_threads WHERE thread_id = ?"
  ],
  "checkpointReads": 1,
  "contextTransferReads": 0
}

CHECKPOINT RPC RESULT
{
  "dispatch": {
    "sequence": 173
  },
  "targetThreadId": "13848fe1-2705-460d-b965-374854e5a937",
  "checkpointId": "checkpoint:scope:checkpoint-scope%3Athread%3A6a471562-fa10-4a72-986c-4d6a377c658a%3Aname%3Aroot:name:1",
  "expectedRunId": "run:thread:6a471562-fa10-4a72-986c-4d6a377c658a:ordinal:1",
  "forkedFrom": {
    "type": "run",
    "threadId": "6a471562-fa10-4a72-986c-4d6a377c658a",
    "runId": "run:thread:6a471562-fa10-4a72-986c-4d6a377c658a:ordinal:1"
  },
  "messages": [],
  "lineage": {
    "parentThreadId": "6a471562-fa10-4a72-986c-4d6a377c658a",
    "relationshipToParent": "fork",
    "rootThreadId": "6a471562-fa10-4a72-986c-4d6a377c658a"
  }
}