docs(agent-note): flip the regrouping note to implemented

Move the triplet to implemented/architecture/, rewrite Proposal into a
present-tense Decision, fold Acceptance criteria and Risks into
Consequences (recording what pins the result), retitle the migration
section to what the move actually touched, and repoint the seven
inbound FIXME/README links.

packages/plan/plan-mode/README.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 packages/plan/plan-mode/README.md
-README.md: f2a78fe98b6a85ce91d727e95ddf62e6f77546b7
-README.zh.md: e1b5f111fd8f761fdd8f25558463c0cc327a14be
+README.md: 6c8ba23b76e83665d4f8dcb5ecb41689347f6423
+README.zh.md: b306d5562af21dd9a95bb68c9acfc3f40c52136f

packages/plan/plan-mode/README.md

@@ -22,7 +22,7 @@ The Web client consumes the plugin-owned `/plan` command; other front doors may
 
 ## Session projection
 
-When the composition mounts `ctx.sessionProjections` ([`@deepseek-ai/dsh-session-projection`](../../session-projection/session-projection/README.md)), this package registers the `plan` projection unit under an injected child. The unit folds two event kinds: a `command/run` record named `plan` with recorded `args` sets the wanted target (`off` → inactive, anything else → active), and `plan/mode` commits the logged state and clears it; every other event returns the same state reference. `view` derives `{ active, pending }`, where `pending` is true only while an outstanding selection differs from the logged state — a pure replay quantity, so host restarts, other tabs, and cold reads all recover it from the log alone (the `/plan` handler calls `set()` before any failing path, keeping the logged request and the run plane from forking). The key merges into `SessionProjectionMap` from `src/types.ts` (served to host consumers via `./types` and client aggregates via `./client`); the framework drives the unit and carriers serve the value on the history tail page and the `session/projection` push frame. Compositions without the registry are unaffected.
+When the composition mounts `ctx.sessionProjections` ([`@deepseek-ai/dsh-session-projection`](../../session/session-projection/README.md)), this package registers the `plan` projection unit under an injected child. The unit folds two event kinds: a `command/run` record named `plan` with recorded `args` sets the wanted target (`off` → inactive, anything else → active), and `plan/mode` commits the logged state and clears it; every other event returns the same state reference. `view` derives `{ active, pending }`, where `pending` is true only while an outstanding selection differs from the logged state — a pure replay quantity, so host restarts, other tabs, and cold reads all recover it from the log alone (the `/plan` handler calls `set()` before any failing path, keeping the logged request and the run plane from forking). The key merges into `SessionProjectionMap` from `src/types.ts` (served to host consumers via `./types` and client aggregates via `./client`); the framework drives the unit and carriers serve the value on the history tail page and the `session/projection` push frame. Compositions without the registry are unaffected.
 
 ## Configuration
 

packages/plan/plan-mode/README.zh.md

@@ -22,7 +22,7 @@ Web 客户端使用该插件提供的 `/plan` 命令；其他入口可以直接
 
 ## 会话投影
 
-当组合挂载 `ctx.sessionProjections`（[`@deepseek-ai/dsh-session-projection`](../../session-projection/session-projection/README.md)）时，本包会在一个注入的子插件中注册 `plan` 投影单元。该单元折叠两类事件：名为 `plan` 且携带已记录 `args` 的 `command/run` 记录会设置目标状态（`off` → 未激活，其余 → 激活），`plan/mode` 会提交已记录状态并清除该目标；其他任何事件都返回同一个状态引用。`view` 推导 `{ active, pending }`，其中 `pending` 仅在尚未落实的选择与已记录状态不同时为 true。该值完全由日志回放得出，因此 host 重启、其他标签页和冷读都能仅凭日志恢复它。`/plan` 处理器会在任何可能失败的路径之前调用 `set()`，避免已写入日志的请求与运行面分叉。key 由 `src/types.ts` 通过声明合并加入 `SessionProjectionMap`：host 消费方经 `./types` 获取，client 聚合经 `./client` 获取。框架负责驱动该单元，载体通过历史尾页和 `session/projection` 推送帧提供其值。未挂载注册表的组合不受影响。
+当组合挂载 `ctx.sessionProjections`（[`@deepseek-ai/dsh-session-projection`](../../session/session-projection/README.md)）时，本包会在一个注入的子插件中注册 `plan` 投影单元。该单元折叠两类事件：名为 `plan` 且携带已记录 `args` 的 `command/run` 记录会设置目标状态（`off` → 未激活，其余 → 激活），`plan/mode` 会提交已记录状态并清除该目标；其他任何事件都返回同一个状态引用。`view` 推导 `{ active, pending }`，其中 `pending` 仅在尚未落实的选择与已记录状态不同时为 true。该值完全由日志回放得出，因此 host 重启、其他标签页和冷读都能仅凭日志恢复它。`/plan` 处理器会在任何可能失败的路径之前调用 `set()`，避免已写入日志的请求与运行面分叉。key 由 `src/types.ts` 通过声明合并加入 `SessionProjectionMap`：host 消费方经 `./types` 获取，client 聚合经 `./client` 获取。框架负责驱动该单元，载体通过历史尾页和 `session/projection` 推送帧提供其值。未挂载注册表的组合不受影响。
 
 ## 配置