refactor(session-projection): compact checkpoint row fields to ver/seq/val

The persisted row (sessionId, key, stateVersion, observedSeq, state)
becomes (sessionId, key, ver, seq, val) — the cache medium repeats these
three names for every unit of every session, so the long forms dominated
the JSON payload. ProjectionCheckpointRow and the checkpointRow zod spec
rename together; the domain spec bumps to v3 (cache semantics: the old
medium is discarded, not migrated). The unit-facing declaration keeps
stateVersion — only the persisted/checkpoint row shape changes.

.agents/notes/proposed/architecture/2026-07-27-session-projection-and-command-log.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write .agents/notes/proposed/architecture/2026-07-27-session-projection-and-command-log.md
-2026-07-27-session-projection-and-command-log.md: 51cc60208ecafd55738c12f1887056c7b0427117
-2026-07-27-session-projection-and-command-log.zh.md: 71f6f6ea944c7c1bdd7e560ec8f0dc2528522fc1
+2026-07-27-session-projection-and-command-log.md: 6a073c956c27bbfc65cff2d4f44ca12023df0cd5
+2026-07-27-session-projection-and-command-log.zh.md: 500f07968db049e4a174ff3b7a075bfe095283db

.agents/notes/proposed/architecture/2026-07-27-session-projection-and-command-log.md

@@ -51,7 +51,7 @@ declare module 'cordis' {
 
 - Values are wire JSON payloads; the same map typed end to end (host unit, wire block, React hook) via `import type` — no second DTO table, no separate client-side "views" map. How a value is *rendered* is the slot system's business, never the projection layer's.
 - **The host is the only place a projection is computed.** The framework drives every registered unit forward eagerly: each committed session event passes through `apply`; a unit uninterested in an event returns the same state reference, and an unchanged reference (`Object.is`) produces no downstream work. Clients never fold domain events — they receive finished values (baseline block + push frame below). This removes the double-implementation trap (plan's two-event fold written once, on the host) and any client-side domain code.
-- **State is always computed, never logged.** The log holds events only; the unit's state lives in the framework's per-session watermark cache (`{state, observedSeq}` per unit) and, in a later phase, in a **persisted projection cache** on the domain-KV storage seam: rows of `(sessionId, key, stateVersion, observedSeq, stateJson)`. A row is never wrong, only possibly stale — `observedSeq` says exactly how stale. The one read recipe, cold and live alike: take the cached state (or `init()`), forward-apply only the events past its watermark, `view` the result. Cold listings (every session's title across all workspaces) become an index read plus, at worst, a short tail replay; the session-persistence seam grows a read-from-seq primitive for that tail in the same later phase. Write policy: throttled (count/interval, configurable) plus two mandatory points — `turn/end` and detach (the live-to-cold moment). A crash between writes costs a longer tail replay, never a wrong value.
+- **State is always computed, never logged.** The log holds events only; the unit's state lives in the framework's per-session watermark cache (`{state, observedSeq}` per unit) and, in a later phase, in a **persisted projection cache** on the domain-KV storage seam: rows of `(sessionId, key, ver, seq, val)` (`ver` = the unit's `stateVersion`, `seq` = the watermark, `val` = the state JSON). A row is never wrong, only possibly stale — its `seq` says exactly how stale. The one read recipe, cold and live alike: take the cached state (or `init()`), forward-apply only the events past its watermark, `view` the result. Cold listings (every session's title across all workspaces) become an index read plus, at worst, a short tail replay; the session-persistence seam grows a read-from-seq primitive for that tail in the same later phase. Write policy: throttled (count/interval, configurable) plus two mandatory points — `turn/end` and detach (the live-to-cold moment). A crash between writes costs a longer tail replay, never a wrong value.
 - A domain's input event set is its own choice: todos folds `todo/write` alone; plan folds `plan/mode` plus its own `/plan` `command/run` records (see the plan section); goal folds `goal/change` metadata; session title folds its title events (retiring the bespoke `session/title` frame and the client's title-snapshot map — the fourth hand-rolled projection this seam absorbs).
 - Registration is an effect (disposer with the fiber): an unloaded plugin's key disappears from subsequent responses and the client reads it as capability absence — HMR semantics for free. Duplicate keys throw. Domain plugins register under `ctx.inject(['sessionProjections'], …)` so headless assemblies without the registry stay unaffected.
 - The package owns `./invariant` (every served key has a live registration).
@@ -133,7 +133,7 @@ Infrastructure first; the three in-flight PRs are left untouched and re-target a
 2. **Client base**: the generic value store + `useProjection` seat; retire the per-domain cell machinery and, with title's unit registered, the `session/title` frame and title-snapshot map. Depends on 1 for the frame shape (fixtures feed synthetic frames meanwhile).
 3. **Command channel**: the two events, executor logging, generic node + keyed slot, notice retirement, `{matched, commandId?}` admission. Parallel with 1.
 4. **Domain re-targets** (after 1+2): todo (unit in `tool-todo`, drop the rider field), then plan (two-event unit, RPCs retired, toggle → `/plan`), then goal (`goal/change` unit, drop `goals.get`, move the six `Session` methods into the domain plugin's inject).
-5. **Persisted projection cache** (later phase, after the domain-KV storage seam): the `(sessionId, key, stateVersion, observedSeq, state)` rows, throttled writes with turn/end + detach mandatory points, and the persistence read-from-seq primitive for cold tail replay.
+5. **Persisted projection cache** (later phase, after the domain-KV storage seam): the `(sessionId, key, ver, seq, val)` rows, throttled writes with turn/end + detach mandatory points, and the persistence read-from-seq primitive for cold tail replay.
 
 ## Alternatives considered
 

.agents/notes/proposed/architecture/2026-07-27-session-projection-and-command-log.zh.md

@@ -51,7 +51,7 @@ declare module 'cordis' {
 
 - 值就是协议层的 JSON 载荷；同一张类型表经 `import type` 端到端贯通（host 侧单元、协议块、React 钩子）——没有第二张 DTO 表，也没有独立的客户端「views」表。值如何*渲染*是 slot 体系的事，永远不归投影层管。
 - **host 是投影唯一的计算地点。** 框架正向驱动（eager drive）每个已注册的单元：每个已提交的会话事件都经过 `apply`；对某事件不感兴趣的单元返回同一个状态引用，而引用未变（`Object.is`）就不产生任何下游工作。客户端从不折叠领域事件——它们收到的是成品值（基线块 + 下文的推送帧）。这消除了双重实现陷阱（plan 的双事件折叠只在 host 写一遍），也消除了一切客户端侧领域代码。
-- **状态永远靠计算得出，绝不入日志。** 日志只存事件；单元的状态住在框架的按会话水位线缓存里（每单元一份 `{state, observedSeq}`），并在后续阶段进入 domain-KV 存储 seam 上的**持久投影缓存（persisted projection cache）**：形如 `(sessionId, key, stateVersion, observedSeq, stateJson)` 的行。一行永远不会是错的，至多是陈旧的——`observedSeq` 精确说明陈旧到哪。冷读与活读共用同一套读取配方：取缓存状态（或 `init()`），只对超出其水位线的事件做正向 `apply`，再对结果做 `view`。冷列表（跨全部 workspace 列出每个会话的标题）变成一次索引读，至多外加一小段尾部回放；session-persistence seam 在同一后续阶段为这段尾部补一个按 seq 起读的原语。写入策略：节流（次数/间隔，可配置）外加两个强制点——`turn/end` 与 detach（由活转冷的时刻）。两次写入之间崩溃的代价是尾部回放更长一些，绝不会是值出错。
+- **状态永远靠计算得出，绝不入日志。** 日志只存事件；单元的状态住在框架的按会话水位线缓存里（每单元一份 `{state, observedSeq}`），并在后续阶段进入 domain-KV 存储 seam 上的**持久投影缓存（persisted projection cache）**：形如 `(sessionId, key, ver, seq, val)` 的行（`ver` = 单元的 `stateVersion`，`seq` = 水位线，`val` = 状态 JSON）。一行永远不会是错的，至多是陈旧的——其 `seq` 精确说明陈旧到哪。冷读与活读共用同一套读取配方：取缓存状态（或 `init()`），只对超出其水位线的事件做正向 `apply`，再对结果做 `view`。冷列表（跨全部 workspace 列出每个会话的标题）变成一次索引读，至多外加一小段尾部回放；session-persistence seam 在同一后续阶段为这段尾部补一个按 seq 起读的原语。写入策略：节流（次数/间隔，可配置）外加两个强制点——`turn/end` 与 detach（由活转冷的时刻）。两次写入之间崩溃的代价是尾部回放更长一些，绝不会是值出错。
 - 领域的输入事件集由领域自己选择：todos 只折叠 `todo/write`；plan 折叠 `plan/mode` 外加它自己的 `/plan` `command/run` 记录（见 plan 一节）；goal 折叠 `goal/change` 元数据；会话标题折叠其标题事件（顺带下线专设的 `session/title` 帧与客户端的标题快照表——这是该 seam 收编的第四个手工投影）。
 - 注册是 effect（disposer 随 fiber 走）：插件卸载后其 key 从后续响应中消失，客户端将其读作能力缺失——HMR（热模块替换）语义随之自动成立。key 重复直接 throw。领域插件在 `ctx.inject(['sessionProjections'], …)` 下注册，因此不带注册表的 headless 组装完全不受影响。
 - 该包拥有 `./invariant`（每个被服务的 key 都有一条存活的注册）。
@@ -133,7 +133,7 @@ host 侧命令执行器（`packages/ui/commands`）在调用处理器前追加 `
 2. **客户端基座**：通用值仓 + `useProjection` 席位；下线按领域的 cell 机制，并在标题单元注册后一并下线 `session/title` 帧与标题快照表。帧的形状依赖 1（在此之前 fixture（测试前置数据）喂合成帧）。
 3. **命令通道**：两个事件、执行器落日志、通用节点 + keyed slot、通知通道下线、`{matched, commandId?}` 准入。与 1 并行。
 4. **领域重新对接**（在 1+2 之后）：先 todo（单元进 `tool-todo`，删掉搭载字段），再 plan（双事件单元、RPC 下线、开关改发 `/plan`），最后 goal（`goal/change` 单元，删掉 `goals.get`，把六个 `Session` 方法移入领域插件的 inject）。
-5. **持久投影缓存**（后续阶段，待 domain-KV 存储 seam 就绪后）：`(sessionId, key, stateVersion, observedSeq, state)` 行、带 turn/end 与 detach 强制点的节流写入，以及持久化侧供冷尾部回放用的按 seq 起读原语。
+5. **持久投影缓存**（后续阶段，待 domain-KV 存储 seam 就绪后）：`(sessionId, key, ver, seq, val)` 行、带 turn/end 与 detach 强制点的节流写入，以及持久化侧供冷尾部回放用的按 seq 起读原语。
 
 ## Alternatives considered