Merge latest origin/master into feat/tui-package

Bring in the one-session surface manager landed through #376 after master advanced beyond the prior merge base.

Resolve the generated event-matrix overlap by regenerating from the merged TypeScript tree, preserving master's updated session declaration locations together with the TUI listener edges. Regenerate and verify the RFC index so both lifecycle updates remain represented.

docs/rfc/implemented/architecture/2026-06-18-session-surface.md

@@ -31,7 +31,7 @@ export type SurfaceOp =
 
 ### SurfaceManager: delta-based, not full rebuild
 
-A `SurfaceManager` class (private to `Session`) maintains one ordered `number[]` of event seqs. It tracks `_lastProcessedSeq` and processes only the new events since the last access rather than rescanning the entire log. Because the log is append-only, prior events never change; a seeded log is simply the initial suffix folded on first access. Replace locates its inclusive endpoints by array position and splices the replacement seq into that range; no link objects or seq-to-node map duplicate the order.
+A `Session` owns one `SurfaceManager` that maintains an ordered `number[]` of event seqs. The manager validates each seed or append candidate without applying it before commit, then processes only committed events since its previous synchronization rather than rescanning the entire log. `Session.surface` exposes the same manager through the readonly `SessionSurface` contract, so acceptance, derived history, compaction, and workspace context share one incremental state. Replace locates its inclusive endpoints by array position and splices the replacement seq into that range; no second manager, link objects, or seq-to-node map duplicates the order.
 
 Delta processing is O(1) when no new events and O(new events) when new events arrive.
 
@@ -60,7 +60,7 @@ Every surface-eligible event must carry `surfaceOp` or it would disappear from d
 
 ## Consequences
 
-- **`packages/core/session`**: `surface.ts` (`SurfaceManager`) maintains one ordered seq array; `SurfaceOp`/`SurfaceIntent` and the top-level session-event fields record how entries join it. `append()` requires a `SurfaceIntent` for surface events, `deriveMessages()` walks the surface as the sole derivation path, and `repair.ts` emits surface-aware closers. The seed constructor rejects a surface-eligible seed event missing its `surfaceOp` marker (see § Invariants).
+- **`packages/core/session`**: `surface.ts` (`SurfaceManager`) maintains one ordered seq array for candidate acceptance and live projection; `SessionSurface` is its readonly public view. `SurfaceOp`/`SurfaceIntent` and the top-level session-event fields record how entries join it. `append()` requires a `SurfaceIntent` for surface events, `deriveMessages()` walks the surface as the sole derivation path, and `repair.ts` emits surface-aware closers. The seed constructor rejects a surface-eligible seed event missing its `surfaceOp` marker (see § Invariants).
 - **`packages/core/agent-loop`**: All surface-capable appends pass surface opts. Chunk seqs are collected for `assistant/message` provenance; `tool/call` seqs are captured for `tool/result` provenance.
 - **`packages/session-persistence/session-persistence-sqlite`**: Two new nullable TEXT columns (`source_event_seqs`, `surface_op`) on the `events` table; `SCHEMA_VERSION` bumped (bump-and-reject, no migration).
 - **`packages/support/invariants`**: Surface-related validation rules.

docs/rfc/implemented/simplification/2026-07-19-use-one-session-surface-manager.i18n.yaml

@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# 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
+2026-07-19-use-one-session-surface-manager.md: 0c0fd70717ff4b49e8817e88592d0781d9ccbd09
+2026-07-19-use-one-session-surface-manager.zh.md: 6d11c9bb475b0ee5a568f96678d0251f1160dda3

docs/rfc/implemented/simplification/2026-07-19-use-one-session-surface-manager.md

@@ -0,0 +1,37 @@
+# RFC: Use one surface manager per session
+
+Status: implemented
+
+English | [中文](2026-07-19-use-one-session-surface-manager.zh.md)
+
+## Problem
+
+`Session` maintained two `SurfaceManager` instances over the same append-only event log. One validated seed and append candidates, while a second lazy instance independently folded committed events for `session.surface`, derived messages, compaction, and workspace context. Once the public surface had been read, every later event advanced duplicate node and replacement-generation state without creating a separate authority or failure boundary.
+
+## Decision
+
+Each `Session` owns one eagerly constructed `SurfaceManager`. Seed and append acceptance call `validateNext()` on that manager before committing an event, and `session.surface` returns the same object through this readonly contract:
+
+```ts
+export interface SessionSurface {
+  readonly nodes: readonly number[]
+  readonly replaceGeneration: number
+}
+```
+
+Candidate validation remains atomic. `validateNext()` may synchronize committed log entries, but it only plans the uncommitted candidate. The candidate enters manager state after `log.push()` and the next delta synchronization, so surface validation failures and pre-commit `internal/dispatch` vetoes leave no phantom node or replacement generation.
+
+`foldSurface()` remains the detached full-log replay function for offline validation and reconstruction. It uses the same transitions and agrees with the live manager for every committed prefix without sharing mutable state.
+
+## Alternatives considered
+
+**Keep acceptance and projection state separate.** Separate instances appeared to isolate public reads from validation, but callers already receive borrowed surface state and the declared readonly contract prevents ordinary mutation. Duplicating the manager was not a runtime trust boundary.
+
+**Recompute the public surface from the full log on every access.** This removed duplicate cached state but gave up incremental derivation and made repeated request construction scale with complete session history.
+
+## Consequences
+
+- Acceptance, `session.surface`, derived messages, compaction, and workspace context observe one incremental state.
+- `Session.surface` exposes no validation method, while its object identity and borrowed readonly node array remain stable.
+- A hostile cast can still corrupt borrowed state; JavaScript callers that deliberately bypass the readonly contract remain outside the supported same-process boundary.
+- Surface, seed, dispatch-veto, request-reconstruction, compaction, and workspace-context tests exercise the shared manager and detached replay paths.

docs/rfc/implemented/simplification/2026-07-19-use-one-session-surface-manager.zh.md

@@ -0,0 +1,37 @@
+# RFC: 每个会话只使用一个表层管理器
+
+Status: implemented
+
+[English](2026-07-19-use-one-session-surface-manager.md) | 中文
+
+## 问题
+
+`Session` 曾针对同一份仅追加事件日志维护两个 `SurfaceManager` 实例。一个实例负责校验种子事件和追加候选事件，另一个延迟创建的实例则独立折叠已提交事件，供 `session.surface`、派生消息、压缩（compaction）和工作区上下文使用。一旦读取公共表层，之后的每个事件都会推进两份重复的节点状态与替换代数状态，却没有形成独立真源或失败边界。
+
+## 决策
+
+每个 `Session` 主动创建并只持有一个 `SurfaceManager`。种子事件与追加事件的接纳流程在提交事件之前调用该管理器的 `validateNext()`，`session.surface` 则通过以下只读契约返回同一个对象：
+
+```ts
+export interface SessionSurface {
+  readonly nodes: readonly number[]
+  readonly replaceGeneration: number
+}
+```
+
+候选事件校验仍保持原子性。`validateNext()` 可以同步已提交的日志事件，但对尚未提交的候选事件只制定变更计划。候选事件在 `log.push()` 之后、下一次增量同步时才进入管理器状态，因此表层校验失败或提交前 `internal/dispatch` 否决都不会留下虚假节点或替换代数。
+
+`foldSurface()` 仍是离线校验与重建使用的分离式完整日志回放函数。它使用相同的状态转换，并且对每个已提交前缀都与活跃管理器一致，但不共享可变状态。
+
+## 备选方案
+
+**继续分离接纳状态与投影视图。** 两个独立实例看似能够隔离公共读取和校验，但调用方取得的本来就是借用的表层状态，声明的只读契约会阻止普通修改。复制管理器并不能构成运行时信任边界。
+
+**每次读取都根据完整日志重新计算公共表层。** 该方案能消除重复缓存状态，但会放弃增量派生，使每次请求构造都随完整会话历史增长。
+
+## 影响
+
+- 接纳流程、`session.surface`、派生消息、压缩和工作区上下文观察同一份增量状态。
+- `Session.surface` 不暴露校验方法，同时保持对象标识和借用的只读节点数组稳定。
+- 恶意类型断言仍可破坏借用状态；刻意绕过只读契约的 JavaScript 调用方不属于受支持的同进程边界。
+- 表层、种子、调度否决、请求重建、压缩和工作区上下文测试覆盖共享管理器与分离回放路径。