fix(pr): keep known state in sync across controls

apps/web/src/state/pullRequests.test.ts

@@ -2,7 +2,11 @@ import { SourceControlProviderKind } from "@t3tools/contracts";
 import { ProjectId, type PullRequestSummary } from "@t3tools/contracts";
 import { describe, expect, it } from "vite-plus/test";
 
-import { newestPullRequestObservation, newestPullRequestSummary } from "./pullRequests";
+import {
+  newestPullRequestObservation,
+  newestPullRequestSummary,
+  threadPullRequestLinkToSummary,
+} from "./pullRequests";
 
 function summary(overrides: Partial<PullRequestSummary> = {}): PullRequestSummary {
   return {
@@ -81,4 +85,35 @@ describe("pull request summary cache", () => {
     expect(newestPullRequestSummary(older, reopened)).toBe(reopened);
     expect(newestPullRequestSummary(reopened, older)).toBe(reopened);
   });
+
+  it("reuses saved thread state while detail is stale and lets newer detail replace it", () => {
+    const stale = summary();
+    const link = {
+      host: "github.com",
+      repository: stale.repository,
+      number: stale.number,
+      url: stale.url,
+      source: "manual" as const,
+      linkedAt: stale.updatedAt,
+      stack: null,
+      snapshot: {
+        ...stale,
+        state: "closed" as const,
+        isDraft: false,
+        updatedAt: "2026-09-11T00:00:00Z",
+        syncedAt: "2026-09-12T00:00:00Z",
+      },
+    };
+    const saved = threadPullRequestLinkToSummary(link, stale.projectId);
+    expect(newestPullRequestSummary(stale, saved)?.state).toBe("closed");
+    const fresh = summary({ isDraft: true, updatedAt: "2026-09-13T00:00:00Z" });
+    expect(newestPullRequestSummary(fresh, saved)).toBe(fresh);
+    expect(threadPullRequestLinkToSummary({ ...link, snapshot: null }, stale.projectId)).toBeNull();
+    expect(
+      threadPullRequestLinkToSummary(
+        { ...link, snapshot: { ...link.snapshot, updatedAt: null } },
+        stale.projectId,
+      ),
+    ).toBeNull();
+  });
 });

apps/web/src/state/pullRequests.ts

@@ -1,17 +1,24 @@
 import { useAtomValue } from "@effect/atom-react";
+import { sourceControlClients } from "@t3tools/client-runtime/source-control-clients";
 import {
   createLinkedPullRequestSummaryAtomFamily,
   createPullRequestEnvironmentAtoms,
   createPullRequestStackAtomFamily,
 } from "@t3tools/client-runtime/state/pull-requests";
 import type {
   EnvironmentId,
+  ProjectId,
   PullRequestListInput,
   PullRequestListStatsInput,
   PullRequestListEntry,
   PullRequestRef,
   PullRequestSummary,
+  ThreadPullRequestLink,
 } from "@t3tools/contracts";
+import {
+  threadPullRequestKeyOf,
+  visibleThreadPullRequests,
+} from "@t3tools/shared/threadPullRequests";
 import * as Option from "effect/Option";
 import { AsyncResult, Atom } from "effect/reactivity";
 import { useCallback, useLayoutEffect, useMemo } from "react";
@@ -24,6 +31,7 @@ import {
   type MergedPullRequestList,
 } from "../components/pullRequest/pullRequestList.logic";
 import { formatEnvironmentQueryError } from "./query";
+import { environmentThreadShells } from "./threads";
 
 export const pullRequestEnvironment = createPullRequestEnvironmentAtoms(connectionAtomRuntime);
 export const linkedPullRequestDetailAtom = createLinkedPullRequestSummaryAtomFamily(
@@ -149,6 +157,58 @@ function observePullRequestSummary(
   });
 }
 
+export function threadPullRequestLinkToSummary(
+  link: ThreadPullRequestLink,
+  projectId: ProjectId,
+): PullRequestSummary | null {
+  // Without the host update time a snapshot cannot be ordered against a fresh read, so it sits out.
+  const updatedAt = link.snapshot?.updatedAt;
+  if (link.snapshot === null || updatedAt == null) return null;
+  return {
+    ...link.snapshot,
+    provider: (
+      sourceControlClients.findByChangeRequestUrl(link.url) ?? sourceControlClients.get(undefined)
+    ).kind,
+    projectId,
+    repository: link.repository,
+    number: link.number,
+    url: link.url,
+    updatedAt,
+  };
+}
+
+// Saved thread snapshots by environment and host-qualified link, indexed once per shell update
+// rather than per control. The host keeps a link to another forge from matching the project's PR.
+function savedPullRequestKey(
+  environmentId: EnvironmentId,
+  reference: Pick<PullRequestRef, "host" | "repository" | "number">,
+): string {
+  return reference.host === undefined
+    ? ""
+    : `${environmentId}:${threadPullRequestKeyOf({ ...reference, host: reference.host })}`;
+}
+
+const savedPullRequestSummariesAtom = Atom.make((get) => {
+  const summaries = new Map<string, PullRequestSummary>();
+  for (const thread of get(environmentThreadShells.threadShellsAtom)) {
+    for (const link of visibleThreadPullRequests(thread.pullRequests)) {
+      const summary = threadPullRequestLinkToSummary(link, thread.projectId);
+      if (summary === null) continue;
+      const key = savedPullRequestKey(thread.environmentId, link);
+      summaries.set(key, newestPullRequestSummary(summaries.get(key) ?? null, summary) ?? summary);
+    }
+  }
+  return summaries;
+});
+
+const savedPullRequestSummaryAtom = Atom.family((key: string) =>
+  Atom.make((get) => get(savedPullRequestSummariesAtom).get(key) ?? null).pipe(
+    // Shell updates also resend unchanged links; keep their subscribers quiet.
+    Atom.withEquality((previous, next) => JSON.stringify(previous) === JSON.stringify(next)),
+    Atom.setIdleTTL(5 * 60_000),
+  ),
+);
+
 export function useSharedPullRequestSummary(
   environmentId: EnvironmentId | null,
   reference: PullRequestRef | null,
@@ -161,17 +221,24 @@ export function useSharedPullRequestSummary(
       : pullRequestSummaryKey(environmentId, reference);
   const atom = observedPullRequestSummaryAtom(key);
   const observed = useAtomValue(atom);
+  const saved = useAtomValue(
+    savedPullRequestSummaryAtom(
+      environmentId === null || reference === null
+        ? ""
+        : savedPullRequestKey(environmentId, reference),
+    ),
+  );
   useLayoutEffect(() => {
     if (environmentId === null || reference === null || current === null || observedAt === null)
       return;
     observePullRequestSummary(environmentId, reference, current, observedAt);
   }, [current, environmentId, reference, observedAt]);
-  return (
+  const summary =
     newestPullRequestObservation(
       observed,
       current === null || observedAt === null ? null : { summary: current, observedAt },
-    )?.summary ?? current
-  );
+    )?.summary ?? current;
+  return newestPullRequestSummary(summary, saved);
 }
 export const pullRequestStackAtom = createPullRequestStackAtomFamily(
   connectionAtomRuntime,