docs: generate each subsystem's cordis surface into its own page; delete the flat catalogs

Rebuild of the region machinery (PR3) on the post-#904 Typert projection:
renderPageRegion/renderInheritedPage live in dsh-typert-generator beside the
projection; scripts/gen-cordis-catalog.ts owns the curated SERVICE_PAGE /
EVENT_SCOPE_PAGE / SERVICE_WALK_EXEMPTIONS / LINK_MAP partition (fail-loud in
both directions, with the independent Context-merge scan backstopping the
projection's blind spot), spliceRegion, and the guarded pair auto-record.
docs/cordis-catalog/ is deleted: the flat events/services catalogs dissolve
into per-page regions and docs/cordis-catalog/core moves to docs/cordis-api/
with the inherited tier as its own generated page. The partition absorbs the
post-regrouping surface: ctx.typert → invariants.md, ctx.directoryPicker →
workspace.md, skills/* events → skills.md, and the four launcher-provided tui
accessor values join the named exemptions.

docs/subsystems/spill.zh.md

@@ -83,3 +83,35 @@ type SpillLocator = Branded<'SpillLocator'>
 `SpillStore`（`ctx.spillStore`，定义于 [`packages/spill/spill/src/index.ts`](../../packages/spill/spill/src/index.ts)）是只有一个方法的抽象服务：`saveText(input) → Promise<SpillRef>`。它持久保存完整的 `content`，并在实际存储失败（权限、ENOSPC、后端不可用）时拒绝。该 seam 只负责存储：不负责保留策略、工具结果替换或检索／搜索 API。
 
 本地后端（[dsh-spill-local](../../packages/spill/spill-local)）写入 `<root>/session-<hash>/<random>-<safeName>`：根目录是已配置或延迟创建的私有（0700）目录，会话子目录采用 `sha256(sessionId)`，并通过排他的仅所有者可访问写入（`open(path, 'wx', 0o600)`）防止预先植入的符号链接重定向写入。其 `locator` 是本地路径，`retrievalHint` 则告知模型在该路径上使用 `read` 或 `grep`。策略消费方（[dsh-spill-policy](../../packages/spill/spill-policy)）会把超过 `maxInlineBytes` 的纯文本最终结果替换为保留库生成的首尾预览和落盘引用；该过程尽力而为：保存失败时保留原始内联结果，而不会把成功的调用变成 `isError`。
+
+<!-- BEGIN GENERATED cordis-surface (gen-cordis-catalog.ts) — do not edit between markers -->
+
+<a id="cordis-surface"></a>
+
+## Cordis surface
+
+Generated from source by `scripts/gen-cordis-catalog.ts` (verified fresh by `pnpm run verify-cordis-catalog` in doc-sync; regenerate with `pnpm run gen-cordis-catalog`) — this section is byte-identical in both language sides of the page. Signature blocks use a `ts cordis-catalog` fence and keep the original source JSDoc; dispatch modes are defined in the [primer](../cordis-primer.md#dispatch-modes), and the framework-inherited `ctx` surface lives in [cordis-api/inherited.md](../cordis-api/inherited.md).
+
+<a id="ctxspillstore--spillstore-abstract-seam"></a>
+
+### `ctx.spillStore` — `SpillStore` (abstract seam)
+
+Abstract spill storage service. Subclass, implement saveText, and load the subclass as a plugin — it registers as `ctx.spillStore` (one implementation per context; loading a second throws, cordis' standard duplicate-service behavior).
+
+Semantics every implementation must honor:
+
+- saveText persists the FULL `content` verbatim and returns an opaque locator, exact byte length, and model-facing retrieval guidance.
+- Storage is scoped by the request's SaveTextSpill.owner session; the backend chooses a private (not world-readable) location and a collision-free name derived from — never equal to — the caller's `suggestedName`.
+- `saveText` REJECTS on a real storage failure (permissions, ENOSPC, backend unavailable); the caller decides how to degrade (the spill policy treats a rejection as best-effort and keeps the inline result).
+
+```ts cordis-catalog
+/**
+ * Persist `input.content` to a session-scoped spill artifact.
+ * @param input - the owner, provenance, suggested name, and full text to save.
+ * @returns the saved artifact's {@link SpillRef}; rejects on a storage failure.
+ */
+abstract saveText(input: SaveTextSpill): Promise<SpillRef>
+```
+
+Source: [`packages/spill/spill/src/index.ts:45`](../../packages/spill/spill/src/index.ts)
+<!-- END GENERATED cordis-surface -->