refactor(todos): retire Python lifecycle field rules into TypeScript

docs/architecture/rfcs/shared-goal-authority-state-provider-v0.md

@@ -2461,6 +2461,15 @@ Every pull request that claims progress against this RFC follows the
 It declares fixture impact, exercises every affected provider arm, and keeps
 the read-only three-arm rehearsal as a separate promotion gate.
 
+Legacy lifecycle field assembly now calls the single TS field planner described
+in the [TS retirement checkpoint](typescript-control-plane-migration-v0.md#legacy-field-rule-retirement-checkpoint).
+This removes Python decisions without changing the per-goal authority phase:
+unpromoted goals still commit through the locked Markdown writer, while promoted
+goals retain their existing provider transactions and unsupported-field fences.
+The planner neither reads a provider nor grants a lease, CAS receipt, or write
+permission. This checkpoint closes one rule owner, not the remaining mutation
+inventory or local-store/promotion qualification.
+
 ### Next delivery and parallel provider work
 
 Markdown is a **permanent first-class readable projection**. Retire its database

docs/architecture/rfcs/shared-goal-authority-state-provider-v0.zh-CN.md

@@ -1952,6 +1952,14 @@ fence。它不能替代只读三臂演练，因为所有 provider 共享新的 s
 声明 fixture 影响、覆盖所有受影响的 provider arm，并把只读三臂演练保留为独立的
 promotion gate。
 
+Legacy lifecycle 的字段组装现在调用唯一 TS field planner，详见
+[TS 退役检查点](typescript-control-plane-migration-v0.zh-CN.md#legacy-字段规则退役检查点)。
+它删除 Python decision，但不改变逐 goal 的 authority 阶段：未 promotion 的 goal
+仍由持锁 Markdown writer 提交，promoted goal 仍使用既有 provider transaction 与
+unsupported-field fence。planner 不读取 provider，也不授予 lease、CAS receipt 或
+写权限。该检查点闭合的是一个规则 owner，不是剩余 mutation inventory 或本地
+store／promotion 资格化。
+
 ### 下一步交付与并行 provider 工作
 
 Markdown 是**长期保留的一等可读投影**。退役的是它的数据库及业务 writer 权威，

docs/architecture/rfcs/typescript-control-plane-migration-v0.md

@@ -3,7 +3,7 @@
 - Status: Accepted, transaction-payoff phase in progress
 - Proposed by: LoopX maintainers
 - Date: 2026-08-15
-- Last revised: 2026-09-07
+- Last revised: 2026-09-09
 - Scope: an incremental, replacement-first migration of the LoopX control-plane
   core from Python to TypeScript without maintaining two semantic
   implementations
@@ -195,6 +195,32 @@ marker/hint configuration with an explicit compatibility plan. Exact legacy
 lifecycle classification codes and unrelated cadence policies are outside this
 slice; they must not be reported as migrated or globally free of prose rules.
 
+### Legacy field-rule retirement checkpoint
+
+`todos/field_update.ts` now owns the complete metadata intent assembly used by
+the legacy `update`, `claim`, `complete`, and `supersede` line writer: status and
+completion timestamps, omission versus explicit clears, binding precedence,
+removed-policy repair, resume-generation pairing, and completion metadata.
+It composes the existing TS completion rule directly. The replaced Python
+decision branches and the last-caller `todo.completion_state.metadata_updates`
+RPC/facade are removed, not kept as a fallback.
+
+This is a pure plan, not admission or a provider commit. Python still owns
+Markdown lookup/encoding, byte-level no-op detection, locking and external
+effects. Public role/binding admission and the event writer are not declared
+migrated by this slice. Promoted update remains text/note-only; no unsupported
+field gains authority, no goal is promoted, and no third storage path appears.
+Rejected plans now leave even the caller's in-memory line buffer unchanged;
+public rejected transactions were already non-committing.
+
+There is one field-plan crossing per legacy line write. It replaces the former
+metadata RPC on ordinary edits; already-finalized completions with an override
+gain one planning crossing. Cached codec normalization calls remain. This is
+semantic deletion, not a claim of fewer crossings on every command. Retire the
+adapter with its final legacy lifecycle caller after full-goal cutover, or fold
+it into that caller's coarse transaction when migrating the caller; do not grow
+a series of field-level RPCs. Retain Markdown rendering permanently.
+
 ### Next delivery sequence
 
 The destination retains Markdown as a **permanent readable projection**, not a

docs/architecture/rfcs/typescript-control-plane-migration-v0.zh-CN.md

@@ -3,7 +3,7 @@
 - Status：Accepted，transaction-payoff 阶段进行中
 - Proposed by：LoopX maintainers
 - Date：2026-08-15
-- Last revised：2026-09-07
+- Last revised：2026-09-09
 - Scope：LoopX 控制面核心从 Python 到 TypeScript 的增量、replacement-first
   迁移；不长期维护两份语义实现
 - Tracking issue：[#3225](https://github.com/huangruiteng/loopx/issues/3225)
@@ -152,6 +152,28 @@ Python decision，保留独立审阅的 typed case，并通过真实 CLI 验证
 字段的 writer，并用明确兼容计划退役旧 marker/hint 配置。本批不迁移精确的旧
 lifecycle classification code 或其他 cadence policy，不能宣称全局已无文本规则。
 
+### Legacy 字段规则退役检查点
+
+`todos/field_update.ts` 现在持有 legacy `update`、`claim`、`complete`、`supersede`
+line writer 共用的完整 metadata intent 组装：status 与 completion 时间、未传与显式
+清空、binding 优先级、已移除 policy 的修复、resume-generation 配对及 completion
+metadata。它直接组合已有 TS completion rule。被替代的 Python decision 分支，以及
+失去最后调用者的 `todo.completion_state.metadata_updates` RPC/facade 一起删除，
+不保留为 fallback。
+
+这是一份纯 plan，不是 admission 或 provider commit。Python 仍保留 Markdown 定位／
+编码、字节级 no-op 检查、锁与外部 effect；本批不宣称迁完公共 role/binding admission
+或 event writer。Promoted update 仍只支持 text/note：不扩权、不 promotion goal、
+不增加第三条存储路径。plan 拒绝时，现在连调用方的内存行缓冲也保持不变；公共
+事务在拒绝时原本就不会提交。
+
+每次 legacy line write 有一次 field-plan crossing：普通编辑替代原 metadata RPC；
+已经 finalization、携带 override 的 completion 会增加一次 planning crossing。
+带缓存的 codec normalization 调用仍在。这兑现的是语义代码删除，不宣称每个命令
+都减少 round trip。完整 goal cutover 后随最后 legacy lifecycle caller 删除 adapter，
+或者迁移该 caller 时将 plan 折叠进其粗粒度事务；不得继续扩张逐字段 RPC。
+Markdown renderer 长期保留。
+
 ### 下一步交付顺序
 
 终态长期保留 Markdown 作为**可读投影**，不是第二个数据库。本 RFC 负责唯一 typed

loopx/control_plane/effect_runtime_handlers.ts

@@ -58,13 +58,13 @@ import {
   evaluateTodoCompletionFence,
 } from "./todos/completion_fence.ts";
 import {
-  buildTodoCompletionMetadataUpdates,
   normalizeTodoCompletionValue,
   requireTodoCompletionMetadataValue,
   selectTodoCompletionContinuation,
 } from "./todos/completion_state.ts";
 import { reduceTodoCompletionTransaction } from "./todos/completion_transaction.ts";
 import { transitionTodoNextAction } from "./todos/next_action.ts";
+import { planTodoFieldUpdate } from "./todos/field_update.ts";
 import {
   evaluateTodoResumeConditions,
   normalizeTodoResumeWhen,
@@ -364,7 +364,7 @@ export function createEffectRuntimeHandlers(
     ["todo.completion_state.normalize", normalizeTodoCompletionValue],
     ["todo.completion_state.require_metadata", requireTodoCompletionMetadataValue],
     ["todo.completion_state.continuation_for_write", selectTodoCompletionContinuation],
-    ["todo.completion_state.metadata_updates", buildTodoCompletionMetadataUpdates],
+    ["todo.field_update.plan", planTodoFieldUpdate],
     [
       "todo.claim.decide",
       (params) => evaluateCoordinationTodoClaimDecision(

loopx/control_plane/todos/completion_state.py

@@ -36,14 +36,6 @@ def _no_followup_value(value: Any) -> bool | str:
     return value if isinstance(value, bool) else _string_value(value)
 
 
-def _successor_values(value: Any) -> Any:
-    if not value:
-        return []
-    if isinstance(value, (list, tuple, set, str, Mapping)):
-        return list(value)
-    return value
-
-
 def _result(method: str, params: dict[str, Any]) -> Mapping[str, Any]:
     try:
         result = effect_runtime_result(method, params)
@@ -135,44 +127,3 @@ def completion_continuation_for_write(*, no_followup: bool, has_successor: bool)
     if continuation not in {item.value for item in TodoCompletionContinuation}:
         raise RuntimeError("TypeScript completion continuation result shape mismatch")
     return str(continuation)
-
-
-def completion_metadata_updates(
-    block: Mapping[str, Any],
-    *,
-    target_status: str,
-    normalized_status: str | None,
-    completion_continuation: str | None,
-    completion_recovery: str | None,
-    no_followup: bool | None,
-    successor_todo_ids: list[str] | None,
-) -> dict[str, Any]:
-    result = _result(
-        "todo.completion_state.metadata_updates",
-        {
-            "schema_version": TODO_COMPLETION_STATE_REQUEST_SCHEMA,
-            "block": {
-                "no_followup": _no_followup_value(block.get("no_followup")),
-                "completion_continuation": _string_value(
-                    block.get("completion_continuation")
-                ),
-                "successor_todo_ids": _successor_values(
-                    block.get("successor_todo_ids")
-                ),
-            },
-            "target_status": target_status,
-            "normalized_status": normalized_status,
-            "completion_continuation": completion_continuation,
-            "completion_recovery": completion_recovery,
-            "no_followup": no_followup,
-            "successor_todo_ids": successor_todo_ids,
-        },
-    )
-    updates = result.get("updates")
-    if not isinstance(updates, Mapping) or any(
-        key not in {"completion_continuation", "completion_recovery"}
-        or not isinstance(value, str)
-        for key, value in updates.items()
-    ):
-        raise RuntimeError("TypeScript completion metadata updates shape mismatch")
-    return dict(updates)