Merge commit 'refs/codex-unblock/20260723/pr570-master-initial' into worktree/pr570-merge-master-20260723

# Conflicts:
#	.agents/notes/implemented/architecture/2026-06-18-shared-persistence-write-coordinator.md
#	docs/core-data-structures/persistence.md
#	packages/session-persistence/session-persistence/README.md

packages/session-persistence/session-persistence/tests/contract.ts

@@ -96,11 +96,25 @@ export function runPersistenceContract(name: string, make: () => Promise<Contrac
           { type: 'turn/start', seq: 6, time: 7, data: { turn: 2, trigger: { kind: 'message', source: { kind: 'user' } } } },
           { type: 'step/start', seq: 7, time: 8, data: { turn: 2, step: 1 } },
         ])
+        const beforeRepair = (await persistence.listSnapshots())
+          .find(snapshot => snapshot.header.id === m.id)?.revision
+
+        const inspected = await persistence.inspect(m.id)
+        const afterInspect = (await persistence.listSnapshots())
+          .find(snapshot => snapshot.header.id === m.id)?.revision
+        expect(afterInspect).toBe(beforeRepair)
+        expect(inspected.events.map(e => e.type)).toEqual([
+          'turn/start', 'user/message', 'step/start', 'assistant/message', 'step/end', 'turn/end',
+          'turn/start', 'step/start',
+        ])
 
         // load PRESERVES the interrupted turn's events (a turn can be huge — they
         // must not be truncated) and closes the orphaned turn with synthetic
         // boundary events: step/end (the step was open) then turn/end {interrupted}.
         const loaded = await persistence.load(m.id)
+        const afterRepair = (await persistence.listSnapshots())
+          .find(snapshot => snapshot.header.id === m.id)?.revision
+        expect(afterRepair).not.toBe(beforeRepair)
         expect(loaded.events.map(e => e.type)).toEqual([
           'turn/start', 'user/message', 'step/start', 'assistant/message', 'step/end', 'turn/end', // turn 1
           'turn/start', 'step/start', 'step/end', 'turn/end', // turn 2: real events + synthetic closers
@@ -201,18 +215,33 @@ export function runPersistenceContract(name: string, make: () => Promise<Contrac
       try {
         await persistence.create(meta('empty'))
         expect((await persistence.list()).map(m => m.id)).not.toContain(SessionId('empty'))
+        expect((await persistence.listSnapshots()).map(snapshot => snapshot.header.id))
+          .not.toContain(SessionId('empty'))
       } finally {
         await dispose()
       }
     })
 
-    it('list() includes a session once it has events', async () => {
+    it('lists stable lightweight revisions that change after an append', async () => {
       const { persistence, dispose } = await make()
       try {
         const m = meta('s2')
         await persistence.create(m)
         await persistence.append(m.id, oneTurnLog())
         expect((await persistence.list()).map(x => x.id)).toContain(m.id)
+        const first = (await persistence.listSnapshots()).find(snapshot => snapshot.header.id === m.id)
+        const repeated = (await persistence.listSnapshots()).find(snapshot => snapshot.header.id === m.id)
+        expect(first).toBeDefined()
+        expect(repeated?.revision).toBe(first?.revision)
+
+        await persistence.append(m.id, [{
+          type: 'turn/start',
+          seq: 6,
+          time: 7,
+          data: { turn: 2, trigger: { kind: 'message', source: { kind: 'user' } } },
+        }])
+        const changed = (await persistence.listSnapshots()).find(snapshot => snapshot.header.id === m.id)
+        expect(changed?.revision).not.toBe(first?.revision)
       } finally {
         await dispose()
       }

packages/session-persistence/session-persistence/tests/coordinator-contract.ts

@@ -740,11 +740,12 @@ export function runCoordinatorContract(name: string, makeFixture: () => Promise<
       }
     })
 
-    it('load rejects a missing session', async () => {
+    it('load and inspect reject a missing session', async () => {
       const fix = await makeFixture()
       const { ctx, fiber } = await freshCtx(fix)
       try {
         await expect(ctx.sessionPersistence.load(SessionId('nope'))).rejects.toThrow(/not found/)
+        await expect(ctx.sessionPersistence.inspect(SessionId('nope'))).rejects.toThrow(/not found/)
       } finally {
         await fiber.dispose()
         await fix.cleanup()

packages/session-persistence/session-persistence/tests/persistence.spec.ts

@@ -3,8 +3,8 @@ import { Context } from 'cordis'
 import SessionStore, { SessionId, isJsonValue } from '@deepseek-ai/dsh-session'
 import type { Session, SessionEvent, SessionHeader } from '@deepseek-ai/dsh-session'
 import {
-  SessionPersistence, PersistenceCoordinator,
-  type PersistenceBackend, type StoredPrefix,
+  SessionPersistence, SessionPersistenceRevision, PersistenceCoordinator,
+  type PersistenceBackend, type SessionPersistenceSnapshot, type StoredPrefix,
 } from '../src/index.ts'
 import { runPersistenceContract, meta, oneTurnLog } from './contract.ts'
 import { runCoordinatorContract, type CoordinatorFixture } from './coordinator-contract.ts'
@@ -94,6 +94,10 @@ class MemoryPersistence extends SessionPersistence implements PersistenceBackend
     return this.coordinator.load(id)
   }
 
+  inspect(id: SessionId): Promise<{ meta: SessionHeader; events: SessionEvent[] }> {
+    return this.coordinator.inspect(id)
+  }
+
   // --- PersistenceBackend hooks (the Map storage primitives) ---
 
   // A Map-backed store has no torn tails, so `tornMarker` is never set.
@@ -131,6 +135,13 @@ class MemoryPersistence extends SessionPersistence implements PersistenceBackend
   async list(): Promise<SessionHeader[]> {
     return [...this.store.values()].map(e => structuredClone(e.meta))
   }
+
+  async listSnapshots(): Promise<SessionPersistenceSnapshot[]> {
+    return [...this.store.values()].map(entry => ({
+      header: structuredClone(entry.meta),
+      revision: SessionPersistenceRevision(`events:${entry.events.length}`),
+    }))
+  }
 }
 
 /** Controllable storage primitive for serialization and retirement failure tests. */