Merge remote-tracking branch 'origin/master' into codex/remove-stdio-agent

# Conflicts:
#	AGENTS.md
#	docs/config-catalog.md
#	examples/echo-agent/README.md
#	packages/examples/stdio-demo/README.md
#	packages/examples/stdio-demo/src/index.ts
#	packages/examples/stdio-demo/tests/built-bin.e2e.ts
#	packages/examples/stdio-demo/tests/stdio-agent.spec.ts
#	scripts/run-gates.ts

docs/architecture.md

@@ -137,7 +137,7 @@ The session log is the source of truth. `deriveMessages()` projects session even
 
 **Model-visible ⟺ logged**: the log reconstructs every request — messages at `step/start` fronted by the header's session prefix, headers by folding `request/header` — and dev invariants assert this ([reconstructability](../.agents/notes/implemented/architecture/2026-07-05-reconstructable-requests.md)).
 
-Durability is a plugin concern. Persistence backends buffer synchronous `session/event` notifications and the loop awaits a turn-end checkpoint before moving on. The `SessionPersistence` seam stores `SessionEvent` directly, with metadata in `SessionHeader`; JSONL and SQLite share one contract suite.
+Durability is a plugin concern. Backends buffer synchronous `session/event` notifications; the loop awaits a turn-end checkpoint. `SessionPersistence` stores `SessionEvent` directly and metadata in `SessionHeader`; JSONL defaults to checksummed Zstandard, with SQLite under one contract.
 
 ### Model Content
 

docs/config-catalog.md

@@ -58,6 +58,8 @@ export interface Config {
   dshHome?: string
   /** Directory the JSONL session backend writes under. Defaults to `./.sessions`. */
   persistenceRoot?: string
+  /** JSONL artifact encoding; defaults to checksummed Zstandard frames. */
+  persistenceCompression?: JsonlCompression
   /** Controls automatic AGENTS.md/CLAUDE.md loading; configure a byte budget or set `false`. */
   workspaceContext: agentCore.Config['workspaceContext']
   /** Skill registry, local-provider, and model-facing consumer config forwarded to agent-spine-demo. */
@@ -69,9 +71,9 @@ export interface Config {
 }
 ```
 
-Depends on: [`agentCore`](../packages/examples/agent-spine-demo/src/index.ts) · [`ToolsConfig`](#deepseek-aidsh-tools)
+Depends on: [`agentCore`](../packages/examples/agent-spine-demo/src/index.ts) · [`JsonlCompression`](../packages/session-persistence/session-persistence-jsonl/src/index.ts) · [`ToolsConfig`](#deepseek-aidsh-tools)
 
-Source: [`packages/examples/acp-demo/src/index.ts:33`](../packages/examples/acp-demo/src/index.ts)
+Source: [`packages/examples/acp-demo/src/index.ts:36`](../packages/examples/acp-demo/src/index.ts)
 
 ## `@deepseek-ai/dsh-agent-loop`
 
@@ -224,6 +226,8 @@ export interface Config {
   dshHome?: string
   /** Directory the JSONL session backend writes under. Defaults to `./.sessions`. */
   persistenceRoot?: string
+  /** JSONL artifact encoding; defaults to checksummed Zstandard frames. */
+  persistenceCompression?: JsonlCompression
   /** Skill registry, local-provider, and model-facing consumer config. */
   skills?: agentCore.SkillConfig
   /** Model-facing bash tool config forwarded through agent-spine-demo. */
@@ -235,9 +239,9 @@ export interface Config {
 }
 ```
 
-Depends on: [`agentCore`](../packages/examples/agent-spine-demo/src/index.ts) · [`ToolsConfig`](#deepseek-aidsh-tools)
+Depends on: [`agentCore`](../packages/examples/agent-spine-demo/src/index.ts) · [`JsonlCompression`](../packages/session-persistence/session-persistence-jsonl/src/index.ts) · [`ToolsConfig`](#deepseek-aidsh-tools)
 
-Source: [`packages/examples/cli-demo/src/index.ts:22`](../packages/examples/cli-demo/src/index.ts)
+Source: [`packages/examples/cli-demo/src/index.ts:25`](../packages/examples/cli-demo/src/index.ts)
 
 ## `@deepseek-ai/dsh-code-runtime-worker`
 
@@ -738,10 +742,15 @@ export interface Config {
    * (bash calls, subprocesses). Sessions group under per-cwd subdirectories.
    */
   root: string
+  /** Physical encoding; defaults to checksummed Zstandard frames. */
+  compression?: JsonlCompression
 }
+
+/** Physical encoding selected for JSONL session artifacts. */
+export type JsonlCompression = 'zstd' | 'none'
 ```
 
-Source: [`packages/session-persistence/session-persistence-jsonl/src/index.ts:24`](../packages/session-persistence/session-persistence-jsonl/src/index.ts)
+Source: [`packages/session-persistence/session-persistence-jsonl/src/index.ts:36`](../packages/session-persistence/session-persistence-jsonl/src/index.ts)
 
 ## `@deepseek-ai/dsh-session-persistence-sqlite`
 
@@ -1263,6 +1272,8 @@ export interface Config {
   dshHome?: string
   /** Directory the JSONL session backend writes under. Defaults to `./.sessions`. */
   persistenceRoot?: string
+  /** JSONL artifact encoding; defaults to checksummed Zstandard frames. */
+  persistenceCompression?: JsonlCompression
   /** TUI subtitle rendered on start. Defaults to `ready.`. */
   welcome?: string
   /** Full-screen TUI presentation settings. */
@@ -1280,9 +1291,9 @@ export interface Config {
 }
 ```
 
-Depends on: [`agentCore`](../packages/examples/agent-spine-demo/src/index.ts) · [`ToolsConfig`](#deepseek-aidsh-tools) · [`uiTui`](../packages/ui/tui/src/index.ts)
+Depends on: [`agentCore`](../packages/examples/agent-spine-demo/src/index.ts) · [`JsonlCompression`](../packages/session-persistence/session-persistence-jsonl/src/index.ts) · [`ToolsConfig`](#deepseek-aidsh-tools) · [`uiTui`](../packages/ui/tui/src/index.ts)
 
-Source: [`packages/examples/tui-demo/src/index.ts:28`](../packages/examples/tui-demo/src/index.ts)
+Source: [`packages/examples/tui-demo/src/index.ts:31`](../packages/examples/tui-demo/src/index.ts)
 
 ## `@deepseek-ai/dsh-user-approval`
 

docs/core-data-structures/persistence.md

@@ -102,7 +102,7 @@ Replay/fork is therefore `ctx.sessions.create(id, { seed: seedEvents })`; resumi
 
 Both implement the same abstract `SessionPersistence` (locate/create/append/load/list over `SessionEvent`) and pass `runPersistenceContract`, proving the seam is genuinely backend-agnostic:
 
-- **[dsh-session-persistence-jsonl](../../packages/session-persistence/session-persistence-jsonl)** — an append-only JSONL log per session with crash-safe atomic writes, the interrupted-turn crash recovery above, and a read/replay path.
+- **[dsh-session-persistence-jsonl](../../packages/session-persistence/session-persistence-jsonl)** — an append-only logical JSONL log per session, stored as checksummed concatenated Zstandard frames by default or raw lines by configuration, with crash-safe atomic writes, interrupted-turn recovery, and a read/replay path.
 - **[dsh-session-persistence-sqlite](../../packages/session-persistence/session-persistence-sqlite)** — `node:sqlite`, one row per `SessionEvent`. The row shape `(session_id, seq, type, time, data, source_event_seqs, surface_op)` maps 1:1 onto the event, including optional surface metadata, so there is no parallel persisted schema to keep in sync.
 
 Multiple backends sharing one on-disk session coordinate writes through the [shared persistence write-coordinator](../../.agents/notes/implemented/architecture/2026-06-18-shared-persistence-write-coordinator.md).

docs/i18n/terminology.md

@@ -65,6 +65,7 @@
 | waterfall | waterfall | waterfall（瀑布式事件） | | |
 | wheel | wheel 包 | | | Python 打包格式 |
 | worktree | worktree | | | git 工作区概念 |
+| Zstandard | Zstandard | | | RFC 8878 compression format; `zstd` remains a code value. |
 
 ## 双语类（中英文文本各自使用中英文）