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/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 */