docs(notes): record slot-declaration-as-service as future work

deferRegistration() stays the shipped form; the note pins the follow-up
direction (bridge declarations into slot:<name> services, migrate
registrants to nested ctx.inject, delete the helper) and the boundaries
a separate PR must settle.

.agents/notes/proposed/architecture/2026-07-25-client-settings-locale-theme.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
-2026-07-25-client-settings-locale-theme.md: 19a46c5444ea6c56c656b6a17cd024c5897d432c
-2026-07-25-client-settings-locale-theme.zh.md: d8e77ad3106780f6e39583e0bb02c2614fe67829
+2026-07-25-client-settings-locale-theme.md: 0cfa244f7e9856aede3d01a80404a794374e16be
+2026-07-25-client-settings-locale-theme.zh.md: 7caa79d5409b2a11078efb8e52273dc70f89f085

.agents/notes/proposed/architecture/2026-07-25-client-settings-locale-theme.md

@@ -51,7 +51,11 @@ root
             └─ models (order 10)         ui-models 注册
 ```
 
-Section and item contributions both use declaration-aware deferral and do not depend on the client manifest's apply order. The `settings.general.item` SlotMap entry's canonical home is the ui-settings contract; locale/ui-theme, because of the reference cycle (the shell consumes ctx.locale), consume that entry as verbatim duplicated merges, with declaration merging guaranteeing the copies agree.
+Section and item contributions both use declaration-aware deferral (ui-slots' `deferRegistration()`: ledger-judged presence, `refresh()` for localized labels, one-call disposal) and do not depend on the client manifest's apply order. The `settings.general.item` SlotMap entry's canonical home is the ui-settings contract; locale/ui-theme, because of the reference cycle (the shell consumes ctx.locale), consume that entry as verbatim duplicated merges, with declaration merging guaranteeing the copies agree.
+
+### Future work: promote slot declarations to first-class injectable waits
+
+`deferRegistration()` is behaviorally isomorphic to `ctx.inject` — one waits on a ledger declaration, the other on service presence, with matching disappear/reappear lifecycle semantics; the difference is that the fiber form's disposer lifetime naturally equals the declaration's lifetime, so the stale-disposer presence-judging machinery disappears entirely. Direction (a separate PR): SlotsService bridges each slot into a `slot:<name>` service (value = the slot spec) at declaration commit / cascade removal, registrants migrate from `deferRegistration()` to a nested `ctx.inject(['slot:<name>'], cb)`, then `deferRegistration()` is deleted and packages/client/AGENTS.md checklist item 4 is rewritten. Boundaries to pin down: the nested fiber's harmless wait must not be named by the boot fail-loud scan (needs a test); the `slot:` namespace and the silent-wait-on-typo stance; provide keys are flat names (`slot:a.b` is one key, not a property path on `ctx.slots`). This phase keeps the `deferRegistration()` function form.
 
 ### Service contracts
 

.agents/notes/proposed/architecture/2026-07-25-client-settings-locale-theme.zh.md

@@ -51,7 +51,11 @@ root
             └─ models (order 10)         ui-models 注册
 ```
 
-section/item contribution 均使用 declaration-aware deferral，不依赖 client manifest 的 apply 顺序。`settings.general.item` 的 SlotMap 条目正家在 ui-settings contract；locale/ui-theme 因引用环（壳消费 ctx.locale）以逐字重复合并的方式消费该条目，declaration merging 保证副本一致。
+section/item contribution 均使用 declaration-aware deferral（ui-slots 的 `deferRegistration()`：ledger 判在位、`refresh()` 换本地化 label、一键 dispose），不依赖 client manifest 的 apply 顺序。`settings.general.item` 的 SlotMap 条目正家在 ui-settings contract；locale/ui-theme 因引用环（壳消费 ctx.locale）以逐字重复合并的方式消费该条目，declaration merging 保证副本一致。
+
+### Future work：坑位声明升格为可 inject 的一等等待物
+
+`deferRegistration()` 与 `ctx.inject` 行为同构——一个等 ledger 声明、一个等服务在场，消失/重现的生命周期语义一致；差别只在 fiber 版的 disposer 生命周期天然等于声明生命周期，stale-disposer 判在位机器可整体消失。方向（另开 PR）：SlotsService 在声明落账/级联拆除处把每个坑位桥接成 `slot:<name>` 服务（value 为坑位 spec），注册方从 `deferRegistration()` 迁为嵌套 `ctx.inject(['slot:<name>'], cb)`，随后删除 `deferRegistration()` 并改写 packages/client/AGENTS.md checklist 第 4 条。待钉死的边界：嵌套 fiber 的无害等待不被 boot fail-loud 扫描点名（需测试）；`slot:` 名字空间与 typo 静默等待的口径；provide 键是平面名（`slot:a.b` 是一个键，不是 `ctx.slots` 的属性路径）。本期维持 `deferRegistration()` 函数形式。
 
 ### Service contracts