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/bash.md

@@ -219,3 +219,85 @@ interface BashProcessRead {
 ## The service
 
 `BashExecutor` owns `resolve`, foreground `run`, background-process `start`, and the `sandboxMode` capability fact. `dsh-bash-local` owns command defaulting, timeout/abort classification, the terminal environment, and the background read merge; process groups, bounded collectors, spill files, credential scrubbing, and disposal quiescence are the [subprocess service](subprocess.md)'s. `dsh-tool-bash` owns model-facing rendering and adapts background handles into the [generic task runtime](tasks.md). `dsh-bash` owns the shell tools' shared exit-status contract: the exported `parseExitStatus`/`ParsedExitStatus` inverts the `[exit code: N]` / `[killed by signal: X]` markers `dsh-tool-bash`'s `renderResult` and `dsh-tool-pwsh`'s `renderPwshResult` append, and both tools' `presentResult` use it to split the rendered text into the terminal card's output body and its exit-status pill.
+
+<!-- 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="ctxbash--bashexecutor-abstract-seam"></a>
+
+### `ctx.bash` — `BashExecutor` (abstract seam)
+
+Abstract bash execution service. Subclass, implement the abstract methods, and load the subclass as a plugin — it registers as `ctx.bash` (one implementation per context; loading a second throws, which is cordis' standard duplicate-service behavior).
+
+Implementations must honor these semantics:
+
+- run rejects only for infrastructure failures. Nonzero exits, timeout kills, and abort kills resolve with a BashRunResult.
+- start returns immediately; no timeout applies to background processes. `done` settles at process close and never rejects; spawn failures settle as `killed` with the error on stderr.
+- BashProcess.readOutput is incremental: consecutive reads never repeat output. Lossy reads report truncation and available spill files.
+- A still-running background process is stopped and awaited when its owning composition tears down. With the subprocess seam that boundary is `ctx.subprocess` disposal, so a background process survives an executor-only reload.
+
+```ts cordis-catalog
+/**
+ * Apply implementation-owned defaults and caps to a request before execution.
+ * @param request - the caller's request; omitted fields get this
+ *   implementation's defaults, capped fields are clamped.
+ * @returns the fully-specified spec to hand to {@link run}/{@link start}.
+ */
+abstract resolve(request: BashExecRequest): BashExecSpec
+
+/**
+ * Run a command in the foreground; resolves when it finishes.
+ * @param spec - a resolved spec from {@link resolve}, never a raw request.
+ * @returns the outcome; nonzero exits, timeout kills, and abort kills
+ *   resolve with a descriptive result rather than reject.
+ */
+abstract run(spec: BashExecSpec): Promise<BashRunResult>
+
+/**
+ * Start a background process and return its handle immediately.
+ * @param spec - a resolved spec from {@link resolve}, never a raw request.
+ * @returns the live process handle (reads, kill, quiescence promise).
+ */
+abstract start(spec: BashExecSpec): BashProcess
+```
+
+Source: [`packages/bash/bash/src/index.ts:53`](../../packages/bash/bash/src/index.ts)
+
+<a id="ctxbashenv--bashenvregistry"></a>
+
+### `ctx.bashEnv` — `BashEnvRegistry`
+
+Registry (`ctx.bashEnv`) for trusted, per-execution `DSH_*` variables. The namespace is rebuilt for every model shell call: ambient `DSH_*` values are discarded by the executor, then the registry's current snapshot is injected. Built-in shell facts remain owned by the registry itself while plugins can register additional, enumerable facts with effect-scoped disposal.
+
+```ts cordis-catalog
+/**
+ * Register one environment contributor. Names and keys are unique; built-in
+ * keys are reserved. Registration is disposed with the calling plugin fiber.
+ * @param contributor - declared key ownership and per-execution resolver.
+ * @returns the disposer that unregisters the contribution.
+ */
+register(contributor: BashEnvContributor): () => void
+
+/**
+ * Build the trusted `DSH_*` snapshot for one shell tool execution.
+ * @param execution - the current tool execution.
+ * @returns an immutable environment overlay containing built-ins and current contributions.
+ */
+collect(execution: ToolExecution): DshEnvironment
+
+/**
+ * Enumerate plugin-contributed variables without executing their resolvers.
+ * @returns declarations sorted by environment variable name.
+ */
+list(): BashEnvVariableInfo[]
+```
+
+Types: [DshEnvironment](subprocess.md) · [ToolExecution](tools.md)
+
+Source: [`packages/bash/bash-env/src/index.ts:89`](../../packages/bash/bash-env/src/index.ts)
+<!-- END GENERATED cordis-surface -->