fix(session-persistence): create SQLite databases owner-only

docs/config-catalog.md

@@ -603,8 +603,8 @@ Requires: `sessions`
 export interface Config {
   /**
    * Filesystem path to the SQLite database file. The special value `:memory:`
-   * opens an in-process database (tests); a file path is created (with parent
-   * dirs) on construction.
+   * opens an in-process database (tests). Missing directories and the database
+   * are created with owner-only permissions; existing path modes are preserved.
    */
   path: string
   /**
@@ -627,7 +627,7 @@ export interface Config {
 export type JournalMode = 'wal' | 'delete' | 'truncate' | 'persist'
 ```
 
-Source: [`packages/session-persistence/session-persistence-sqlite/src/index.ts:38`](../packages/session-persistence/session-persistence-sqlite/src/index.ts)
+Source: [`packages/session-persistence/session-persistence-sqlite/src/index.ts:48`](../packages/session-persistence/session-persistence-sqlite/src/index.ts)
 
 ## `@deepseek-ai/dsh-session-query`
 

packages/session-persistence/session-persistence-sqlite/README.md

@@ -8,7 +8,7 @@ A SQLite durable session-persistence backend — a second `SessionPersistence` i
 
 Each `SessionEvent` maps 1:1 onto a row in an `events` table `(session_id, seq, type, time, data, source_event_seqs, surface_op)` — `data` is the event payload as JSON text, so the row shape is the event verbatim (including `assistant/chunk`, keeping `seq` contiguous). The two `TEXT` columns `source_event_seqs` and `surface_op` are nullable; they store the event's optional surface-metadata fields (see [session surface](../../../docs/rfc/implemented/architecture/2026-06-18-session-surface.md)). Out-of-log metadata (`SessionHeader`) lives in a `sessions` row. A `sessions` row is written only by the first `append` — its existence is the lazy-materialization signal (`list` reports exactly the sessions that have a row), so no separate column is needed.
 
-The repository's Node range supports unflagged `node:sqlite`. The database enables foreign keys and uses the configured journal mode (`wal` by default; use a rollback mode where WAL shared-memory files are unsuitable). `PRAGMA user_version` stores the table-layout version; databases with any other version are rejected because this unreleased format has no migrations.
+The repository's Node range supports unflagged `node:sqlite`. The database enables foreign keys and uses the configured journal mode (`wal` by default; use a rollback mode where WAL shared-memory files are unsuitable). On filesystems with POSIX modes, missing directories are created as `0700` and a missing database is exclusively created as `0600` before SQLite opens it, causing new WAL sidecars to inherit owner-only access. Existing directories, database files, and sidecars keep their modes; ordinary filesystem access errors still fail initialization. `PRAGMA user_version` stores the table-layout version; databases with any other version are rejected because this unreleased format has no migrations.
 
 ## Contract semantics over rows
 

packages/session-persistence/session-persistence-sqlite/src/index.ts

@@ -8,7 +8,7 @@
 import { Context } from 'cordis'
 import z from 'schemastery'
 import { DatabaseSync } from 'node:sqlite'
-import { mkdir } from 'node:fs/promises'
+import { mkdir, open } from 'node:fs/promises'
 import { dirname, resolve } from 'node:path'
 import {
   SessionPersistence, PersistenceCoordinator,
@@ -34,12 +34,22 @@ function surfaceBindings(event: SessionEvent): [string | null, string | null] {
   ]
 }
 
+/** Create a missing database owner-only while preserving an existing file's mode. */
+async function createDatabaseFile(path: string): Promise<void> {
+  try {
+    const handle = await open(path, 'wx', 0o600)
+    await handle.close()
+  } catch (error) {
+    if ((error as NodeJS.ErrnoException).code !== 'EEXIST') throw error
+  }
+}
+
 /** Plugin configuration. */
 export interface Config {
   /**
    * Filesystem path to the SQLite database file. The special value `:memory:`
-   * opens an in-process database (tests); a file path is created (with parent
-   * dirs) on construction.
+   * opens an in-process database (tests). Missing directories and the database
+   * are created with owner-only permissions; existing path modes are preserved.
    */
   path: string
   /**
@@ -87,6 +97,7 @@ export class SessionPersistenceSqlite extends SessionPersistence implements Pers
     if (path !== ':memory:') {
       const abs = resolve(path)
       await mkdir(dirname(abs), { recursive: true, mode: 0o700 })
+      await createDatabaseFile(abs)
       this.db = openDatabase(abs, journalMode)
     } else {
       this.db = openDatabase(path, journalMode)

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

@@ -1,9 +1,9 @@
 import { afterEach, describe, expect, it } from 'vitest'
 import { Context } from 'cordis'
 import { existsSync } from 'node:fs'
-import { mkdtemp, rm } from 'node:fs/promises'
+import { chmod, mkdtemp, mkdir, rm, stat, writeFile } from 'node:fs/promises'
 import { tmpdir } from 'node:os'
-import { join } from 'node:path'
+import { dirname, join } from 'node:path'
 import SessionStore, { SessionId } from '@deepseek-ai/dsh-session'
 import type { Session, SessionEvent, SurfaceEvent, SurfaceEventType } from '@deepseek-ai/dsh-session'
 import SessionPersistenceSqlite, { SCHEMA_VERSION } from '@deepseek-ai/dsh-session-persistence-sqlite'
@@ -348,6 +348,52 @@ describe('SessionPersistenceSqlite: durability and crash semantics', () => {
 })
 
 describe('SessionPersistenceSqlite: edge cases', () => {
+  it('creates a new database and WAL sidecars owner-only without changing an existing directory mode', async () => {
+    if (process.platform === 'win32') return
+    const path = await freshDbPath()
+    const dir = dirname(path)
+    await chmod(dir, 0o755)
+
+    const b = await backend(path)
+    await b.ctx.sessionPersistence.list()
+
+    expect((await stat(dir)).mode & 0o777).toBe(0o755)
+    expect((await stat(path)).mode & 0o777).toBe(0o600)
+    expect((await stat(`${path}-wal`)).mode & 0o777).toBe(0o600)
+    expect((await stat(`${path}-shm`)).mode & 0o777).toBe(0o600)
+    await b.dispose()
+  })
+
+  it('preserves the mode of an existing database file', async () => {
+    if (process.platform === 'win32') return
+    const path = await freshDbPath()
+    await writeFile(path, '', { mode: 0o644 })
+    await chmod(path, 0o644)
+
+    const ctx = new Context()
+    await ctx.plugin(SessionStore)
+    const fiber = await ctx.plugin(SessionPersistenceSqlite, { path, journalMode: 'delete' })
+    await ctx.sessionPersistence.list()
+
+    expect((await stat(path)).mode & 0o777).toBe(0o644)
+    await fiber.dispose()
+  })
+
+  it('surfaces database pre-creation errors other than an existing file', async () => {
+    if (process.platform === 'win32') return
+    const path = await freshDbPath()
+    const blocked = join(dirname(path), 'blocked')
+    await mkdir(blocked, { mode: 0o500 })
+    const b = await backend(join(blocked, 'sessions.db'))
+
+    try {
+      await expect(b.ctx.sessionPersistence.list()).rejects.toMatchObject({ code: 'EACCES' })
+      await b.dispose()
+    } finally {
+      await chmod(blocked, 0o700)
+    }
+  })
+
   it('append rolls back and rethrows when an event INSERT fails inside the transaction', async () => {
     const path = await freshDbPath()
     const m = meta('rollback-insert')