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/web.md

@@ -133,3 +133,70 @@ Selection never depends on registration, config, or HMR order: a capability has
 ## The service
 
 `WebService` registers search and fetch providers, rejects duplicate ids with `WEB_DUPLICATE_PROVIDER`, and resolves providers at execution time with structured selection errors. The local fetch backend accepts only HTTP(S), rejects credentials, caps redirects, bytes, characters, and time, revalidates every same-origin redirect hop, and decodes the body; the tool owns presentation. Private-network blocking is deferred, so do not enable `web_fetch` where it can reach sensitive internal targets.
+
+<!-- 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="ctxweb--webservice"></a>
+
+### `ctx.web` — `WebService`
+
+The web access service. Registered as `ctx.web` (one instance per context).
+
+Selection semantics (resolved at execution time, never order-dependent):
+
+- A configured id that is registered and `available()` → that provider.
+- A configured id not registered → `WEB_PROVIDER_CONFIGURED_MISSING`.
+- A configured id registered but unavailable → `WEB_PROVIDER_CONFIGURED_UNAVAILABLE`.
+- No id configured, exactly one registered usable provider → that provider.
+- No id configured, multiple usable providers → `WEB_PROVIDER_AMBIGUOUS`.
+- No id configured, no usable provider → `WEB_PROVIDER_UNAVAILABLE`.
+
+```ts cordis-catalog
+/**
+ * Register a search provider. Throws {@link WebError} `WEB_DUPLICATE_PROVIDER`
+ * if its id is already registered for search. Returns a disposer; disposed
+ * with the calling fiber.
+ * @param provider - the provider; its `id` is the registry key.
+ * @returns the disposer that unregisters the provider.
+ */
+registerSearchProvider(provider: WebSearchProvider): () => void
+
+/**
+ * Register a fetch provider. Throws {@link WebError} `WEB_DUPLICATE_PROVIDER`
+ * if its id is already registered for fetch. Returns a disposer; disposed
+ * with the calling fiber.
+ * @param provider - the provider; its `id` is the registry key.
+ * @returns the disposer that unregisters the provider.
+ */
+registerFetchProvider(provider: WebFetchProvider): () => void
+
+/**
+ * Run one search through the selected provider. Resolves the provider at call
+ * time with the selection rules above; throws {@link WebError} when the
+ * capability cannot run. The seam enforces `request.maxResults` on the result:
+ * if the provider over-returns, `sources[]` is truncated and `truncated` set.
+ * @param request - the query plus result-shaping options.
+ * @param signal - optional cancellation signal forwarded to the provider.
+ * @returns the provider's results, capped to `request.maxResults`.
+ */
+async search(request: WebSearchRequest, signal?: AbortSignal): Promise<WebSearchResult>
+
+/**
+ * Retrieve one URL through the selected provider. Resolves the provider at
+ * call time with the selection rules above; throws {@link WebError} when the
+ * capability cannot run. A non-2xx response is a result, not a throw.
+ * @param request - the URL plus retrieval options.
+ * @param signal - optional cancellation signal forwarded to the provider.
+ * @returns the retrieval outcome; non-2xx responses resolve descriptively.
+ */
+async fetch(request: WebFetchRequest, signal?: AbortSignal): Promise<WebFetchResult>
+```
+
+Source: [`packages/web/web/src/index.ts:74`](../../packages/web/web/src/index.ts)
+<!-- END GENERATED cordis-surface -->