fix(client): dé-dupliquer les ensureAccount concurrents au cold-start (fork résolu)

Dernière couche du bug de reconnexion : au cold-start, `watchShape` public +
protected + l'effet owned-events appellent `ensureAccount(A)` quasi-simultanément
AVANT la sync du shim → chacun lit 0 → chacun provisionne un nouveau jeu de docs
(fork par-appelant) → la résolution déterministe canonique fait alors diverger
lecteur et écrivain sur le docProtected → `readScopeIndex` vide.

Fix : `ensureInFlight` (map de promesses) dé-duplique les provisions concurrentes
en UNE seule ; `discovery.readIndex` ouvre son repo au cold-start (`ensureRepoOpen`).
Avec la résolution canonique déjà committée, écrivain et lecteur convergent.
Mesuré (levier isSuccess) : la participation protected converge `isSuccess=true,
data=1` sur la page fraîche (plus « vide à 30s »).

gate : tsc 0 ; bun test 123 ; test:e2e 42/42.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/client/src/discovery.ts

@@ -39,6 +39,7 @@
 
 import * as inbox from "./inbox";
 import { subscribeDoc } from "./subscribe";
+import { ensureRepoOpen } from "./open-repo";
 import { ensureAccount, reservedAccount } from "./store-registry";
 import { getCaps } from "./polyfill";
 import type { Nuri, PrincipalId } from "./types";
@@ -154,6 +155,19 @@ export async function submitToIndex(ref: unknown, opts?: SubmitOptions): Promise
  */
 export async function readIndex(): Promise<IndexEntry[]> {
   const target = await indexInboxNuri();
+  // COLD-START heal (polyfill-era): on a FRESH session over a persistent wallet the
+  // discovery-index inbox repo is not yet in the verifier's `self.repos`, so the
+  // anchored `inbox.read` below would resolve an unopened repo and silently return 0
+  // deposits — the same self-inflicted cold-read gap `readScopeIndex`/`readUnion`
+  // heal. This is what made the PUBLIC read's discovery fold come back empty on a
+  // reconnect, so a fresh page's home stayed empty for tens of seconds while the doc
+  // slowly synced by other means. Open/subscribe the index repo ONCE and await its
+  // first `State` (the sync barrier) before the anchored read. Idempotent per session;
+  // no-op with the unit fake ng (no `doc_subscribe`). This is done HERE (a cold direct
+  // reader) rather than inside `inbox.read`, because `inbox.watch` already holds the
+  // repo open via its own subscription and must not spawn a second bootstrap open. See
+  // open-repo.ts.
+  await ensureRepoOpen(target);
   const deposits = await inbox.read(target);
   const seen = new Set<string>();
   const entries: IndexEntry[] = [];

packages/client/src/inbox.ts

@@ -156,6 +156,13 @@ export async function post(targetInbox: Nuri, opts: PostOptions): Promise<void>
  */
 export async function read(targetInbox: Nuri): Promise<Deposit[]> {
   const sid = await sessionId();
+  // NOTE: cold-start repo opening is done by the COLD DIRECT readers that need it
+  // (e.g. `discovery.readIndex` → `ensureInboxRepoOpen`), NOT here — `inbox.watch`
+  // already holds the repo open via its own `subscribeDoc`, so opening a second
+  // bootstrap subscription from inside a watch's re-read would be redundant and can
+  // race the watch's own initial-`State` delivery. Keeping `read` a pure anchored
+  // read leaves both callers correct: the watch path stays event-driven, and the
+  // cold direct-read path opens the repo explicitly before calling `read`.
   // NO explicit `GRAPH <…>` clause — read the anchored DEFAULT graph (see the
   // note in `post`). The anchor (`targetInbox`) scopes the query to that repo's
   // default graph, exactly where `post` writes.

packages/client/src/store-registry.ts

@@ -381,12 +381,49 @@ async function createDoc(): Promise<Nuri> {
   return docCreate(s.sessionId, "Graph", "data:graph", "store", undefined);
 }
 
+/**
+ * In-flight `ensureAccount` promises, keyed by account key — so CONCURRENT
+ * `ensureAccount(id)` calls for the SAME account share ONE resolve-or-provision.
+ *
+ * ── Why this is load-bearing (the reconnection FORK root cause) ─────────────
+ * On a fresh page over the persistent wallet, SEVERAL independent callers hit
+ * `ensureAccount(A)` near-simultaneously: `watchShape('public')` and
+ * `watchShape('protected')` each resolve their doc set (`listMyEntityDocs` →
+ * `ensureAccount`) and subscribe their container (`scopeIndexDoc` →
+ * `ensureAccount`), plus the app's owned-events effect. Each runs BEFORE the shim
+ * has synced, so each `resolveAccountReliably` reads 0 rows and, independently,
+ * PROVISIONS a brand-new set of scope docs — an account FORK PER caller. Measured:
+ * a single new account accrued EIGHT distinct `docPublic`/`docProtected` values in
+ * one session. `canonicalDoc` then makes a fresh reader pick the lexicographic-min
+ * doc, which differs from the (cached, freshly-created) doc the WRITER wrote into →
+ * the reader lists an empty scope index → the home/participation reads come back
+ * empty (the reconnection bug's last layer).
+ *
+ * De-duping concurrent provisions collapses those N racing provisions into ONE:
+ * the first caller resolves-or-provisions; every concurrent caller awaits the SAME
+ * promise and gets the SAME record, so no duplicate docs are ever minted and writer
+ * and reader converge on one canonical scope doc. Not polling: a bounded in-memory
+ * promise map (mirrors open-repo.ts `inFlight`), cleared the instant it settles.
+ */
+const ensureInFlight = new Map<string, Promise<AccountRecord>>();
+
 /**
  * Ensure an account exists in the shim, creating its 3 scope documents on
  * first sight. Idempotent — returns the existing record if already present.
+ * Concurrency-safe: concurrent calls for the same account share one provision
+ * (see {@link ensureInFlight}) so a fresh page never FORKS the account.
  */
 export async function ensureAccount(id: string): Promise<AccountRecord> {
   const key = accountKey(id);
+  // A completed provision/resolve is cached → no query, no fork risk.
+  const cached = accountCache.get(key);
+  if (cached) return cached;
+  // A concurrent provision for the SAME account is already running → await it,
+  // instead of racing a second (forking) provision. This is the anti-fork guard.
+  const pending = ensureInFlight.get(key);
+  if (pending) return pending;
+
+  const p = (async (): Promise<AccountRecord> => {
     // HOT PATH: targeted O(1) lookup — does THIS account already exist? — instead
     // of a full-shim scan (loadShim). Off the read/write hot path entirely.
     //
@@ -431,6 +468,14 @@ export async function ensureAccount(id: string): Promise<AccountRecord> {
     accountCache.set(key, record);
     cache?.set(key, record);
     return record;
+  })();
+
+  ensureInFlight.set(key, p);
+  try {
+    return await p;
+  } finally {
+    ensureInFlight.delete(key);
+  }
 }
 
 // --- resolvers ------------------------------------------------------------

packages/client/test/store-registry.test.ts

@@ -188,6 +188,27 @@ test("ensureAccount is idempotent (case/@-insensitive key), no extra docs", asyn
   expect(fake.doc_create).toHaveBeenCalledTimes(3); // not 6
 });
 
+test("ensureAccount de-dupes CONCURRENT provisions (anti-fork): one account, 3 docs", async () => {
+  // The reconnection FORK: several callers (watchShape public+protected, the
+  // container subs, the owned-events effect) hit ensureAccount(SAME id) BEFORE
+  // the shim has synced, so each reads 0 rows and independently provisions a new
+  // set of scope docs — N forks, N×3 docs, duplicate docPublic/docProtected in the
+  // shim → a fresh reader picks a different canonical doc than the writer wrote to.
+  // The in-flight de-dup collapses N concurrent provisions into ONE.
+  const results = await Promise.all([
+    ensureAccount("Bob"),
+    ensureAccount("Bob"),
+    ensureAccount("@bob"),
+    ensureAccount("BOB"),
+    ensureAccount("bob"),
+  ]);
+  // Exactly ONE set of 3 docs was created — not 5×3.
+  expect(fake.doc_create).toHaveBeenCalledTimes(3);
+  // Every caller got the SAME record (same docs), so writer/reader can never
+  // disagree on the canonical scope doc.
+  for (const r of results) expect(r).toEqual(results[0]!);
+});
+
 test("loadShim round-trips a persisted account across a cache reset", async () => {
   await ensureAccount("Bob");
   resetRegistryCache(); // force a re-read from the fake store