refactor: relocate demo app bundles to packages/examples/*-demo

Move the agent-spine bundle and the stdio/ACP/JSON-RPC app packages out of
core/ and ui/ into a new packages/examples/ group, renamed with a -demo
suffix so the npm name marks them as non-product surface:

  core/agent-core   -> examples/agent-spine-demo  (dsh-agent-spine-demo)
  ui/stdio-agent    -> examples/stdio-demo        (dsh-stdio-demo)
  ui/acp-agent      -> examples/acp-demo          (dsh-acp-demo)
  ui/jsonrpc-agent  -> examples/jsonrpc-demo      (dsh-jsonrpc-demo)

Update every code/config/test reference and reference-only doc mentions, and
regenerate module-graph, config-catalog, and doc-graphs. The jsonrpc bin
(dsh-jsonrpc-agent) and single-file exe (dsh-jsonrpc-agent-pkg) keep their
names; the SDK runtime-startup surface is reconciled separately.

packages/examples/jsonrpc-demo/README.md

@@ -0,0 +1,27 @@
+# @deepseek-ai/dsh-jsonrpc-demo
+
+Bin-only app that boots an external `cordis.yml`; its [`jsonrpc`](../jsonrpc/README.md) entry serves SDK clients over newline-delimited stdio. The config composes the spine, backends, and serving plugin. `lib/bin.js` is also the [single-executable runtime](../../../docs/rfc/implemented/architecture/2026-07-10-single-file-executable-sdk-runtime-distribution.md) entry.
+
+## Config discovery
+
+The first non-empty channel wins: `$DSH_CORDIS_CONFIG`, then positional `argv[2]`. If neither names an existing file, the bin prints one-line usage to stderr and exits 1; there is no working-directory or built-in fallback. [`dsh-app-boot`](../app-boot/README.md) makes plugin load failures fatal. This protocol does not use `DSH_SNAPSHOT`.
+
+A config without `dsh-jsonrpc` is valid and serves nothing; the bin does not designate a server plugin.
+
+## Exit lifecycle
+
+stdin EOF and `SIGTERM` dispose the root to quiescence and exit 0; `SIGINT` exits 130 after the same disposal. EOF may cut off an in-flight turn as documented in the [distribution RFC](../../../docs/rfc/implemented/architecture/2026-07-10-single-file-executable-sdk-runtime-distribution.md). The `jsonrpc` plugin owns response-before-exit protocol shutdown; both paths are idempotent and safe to race.
+
+## stdout is the protocol
+
+stdout carries only JSON-RPC frames. The bin and boot guards diagnose on stderr, and the config must omit stdout loggers.
+
+## Model Experience
+
+Indirectly, through the plugins loaded from the external `cordis.yml`, which own every model-bound prompt, schema, message, and result; this bin adds none of its own.
+
+## Known Limitations and Deferred Work
+
+- **The bin cannot prove that the config serves JSON-RPC** — a valid config with no `dsh-jsonrpc` entry boots successfully and serves nothing.
+- **No built-in or default config exists** — every launch must provide `DSH_CORDIS_CONFIG` or a positional path, and deployment owns the complete plugin tree and stdout discipline.
+- **stdin EOF cuts off in-flight work** — client disappearance disposes the root immediately; callers that need orderly completion use the protocol-level `shutdown` request.

packages/examples/jsonrpc-demo/package.json

@@ -0,0 +1,41 @@
+{
+  "name": "@deepseek-ai/dsh-jsonrpc-demo",
+  "description": "Bin that boots an external Cordis config for the stdio JSON-RPC SDK runtime",
+  "version": "0.0.1",
+  "private": true,
+  "type": "module",
+  "main": "lib/index.js",
+  "types": "lib/types/index.d.ts",
+  "bin": {
+    "dsh-jsonrpc-agent": "lib/bin.js"
+  },
+  "exports": {
+    ".": {
+      "types": "./lib/types/index.d.ts",
+      "default": "./lib/index.js"
+    },
+    "./bin": {
+      "types": "./lib/types/bin.d.ts",
+      "default": "./lib/bin.js"
+    },
+    "./src/*": "./src/*",
+    "./package.json": "./package.json"
+  },
+  "files": [
+    "lib/index.js",
+    "lib/bin.js",
+    "lib/types/**/*.d.ts",
+    "lib/types/**/*.d.ts.map",
+    "src"
+  ],
+  "license": "BSD-3-Clause",
+  "dependencies": {
+    "@deepseek-ai/dsh-app-boot": "workspace:^"
+  },
+  "peerDependencies": {
+    "cordis": "^4.0.0-rc.7"
+  },
+  "devDependencies": {
+    "cordis": "^4.0.0-rc.7"
+  }
+}

packages/examples/jsonrpc-demo/src/bin.ts

@@ -0,0 +1,52 @@
+#!/usr/bin/env node
+/**
+ * Boots an external `cordis.yml`; its `@deepseek-ai/dsh-jsonrpc` entry serves
+ * newline-delimited JSON-RPC on stdio. `$DSH_CORDIS_CONFIG` wins over `argv[2]`;
+ * empty or missing paths exit 1, with no default config or `DSH_SNAPSHOT` mode.
+ * App-boot owns env loading, Loader guards, and settled-tree startup.
+ * stdin EOF and SIGTERM dispose the root context and exit 0; SIGINT exits 130.
+ * Protocol `shutdown` belongs to the server plugin. Stdout is reserved for frames.
+ *
+ * @module @deepseek-ai/dsh-jsonrpc-demo/bin
+ */
+
+import { existsSync } from 'node:fs'
+import { boot, installFailLoud, loadEnv, resolveConfigPath } from '@deepseek-ai/dsh-app-boot'
+
+const NAME = 'dsh-jsonrpc-agent'
+
+/* v8 ignore start -- composition over tested app-boot/jsonrpc and executable acceptance paths */
+installFailLoud(NAME)
+loadEnv(NAME)
+
+// Env wins over argv; empty values are absent. External config defines the deployment.
+const fromEnv = process.env['DSH_CORDIS_CONFIG']
+const fromArgv = process.argv[2]
+const requested = fromEnv !== undefined && fromEnv !== ''
+  ? fromEnv
+  : fromArgv !== undefined && fromArgv !== '' ? fromArgv : undefined
+const configPath = requested === undefined ? undefined : resolveConfigPath(requested, undefined)
+if (configPath === undefined || !existsSync(configPath)) {
+  process.stderr.write(
+    `usage: ${NAME} <path/to/cordis.yml> (or set DSH_CORDIS_CONFIG=<path>, which wins); the config is required — there is no built-in fallback\n`,
+  )
+  process.exit(1)
+}
+
+const ctx = await boot(NAME, configPath)
+let exiting = false
+
+async function disposeAndExit(code: number): Promise<void> {
+  if (exiting) return
+  exiting = true
+  try {
+    await ctx.fiber.dispose()
+  } finally {
+    process.exit(code)
+  }
+}
+
+process.stdin.on('end', () => { void disposeAndExit(0) })
+process.on('SIGTERM', () => { void disposeAndExit(0) })
+process.on('SIGINT', () => { void disposeAndExit(130) })
+/* v8 ignore stop */

packages/examples/jsonrpc-demo/src/index.ts

@@ -0,0 +1,9 @@
+/**
+ * Bin-only app package: `bin.ts` discovers an external `cordis.yml` and owns
+ * process exit. This module exports no composition plugin; the config chooses
+ * whether to load the {@link @deepseek-ai/dsh-jsonrpc} serving plugin.
+ *
+ * @module @deepseek-ai/dsh-jsonrpc-demo
+ */
+
+export {}

packages/examples/jsonrpc-demo/tsconfig.json

@@ -0,0 +1,21 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "compilerOptions": {
+    "rootDir": "src",
+    "outDir": "lib/types"
+  },
+  "include": [
+    "src"
+  ],
+  "references": [
+    {
+      "path": "../../../vendor/cordis"
+    },
+    {
+      "path": "../../../vendor/loader"
+    },
+    {
+      "path": "../../ui/app-boot"
+    }
+  ]
+}

packages/examples/jsonrpc-demo/tsdown.config.ts

@@ -0,0 +1,15 @@
+import { defineConfig } from 'tsdown'
+
+/**
+ * Build the doc-only module and CLI entry; `tsc -b` supplies declarations.
+ */
+export default defineConfig({
+  entry: ['lib/types/index.js', 'lib/types/bin.js'],
+  outDir: 'lib',
+  format: ['esm'],
+  platform: 'node',
+  target: 'es2024',
+  fixedExtension: false,
+  dts: false,
+  clean: false,
+})