chore: initial scaffolding for SynthesisAgent

Bridge between OpenClaw (multi-channel hub) and interactive Claude Code,
keeping autonomous agent usage on the subscription quota after the
2026-06-15 Agent SDK credit split.

Initial scaffolding only — two submodules with skeletons:

- SynthesisAgent.ClaudePlugin: stdio MCP server registered as a --channels
  source. Declares experimental.claude/channel capability (verified 2026-05-14
  against the official Anthropic discord plugin) and emits
  notifications/claude/channel to push OpenClaw inbound messages into the
  Claude turn loop.

- SynthesisAgent.OpenclawPlugin: process manager + session mapping +
  bridge WebSocket. Currently shaped around a custom ws protocol; will be
  rewritten as a model-provider HTTP server (contractor-agent pattern) so
  OpenClaw routes inbound channel messages through it via /v1/chat/completions.

See STATUS.md for the open punch list and docs/wire-protocol.md for the
(soon-to-change) inter-plugin frame schema.

SynthesisAgent.OpenclawPlugin/core/cli.ts

@@ -0,0 +1,37 @@
+import type { OpenClawPluginApi } from 'openclaw/plugin-sdk/core'
+import type { ProcessManager } from './process-manager.js'
+import type { SessionMapping } from './session-mapping.js'
+import type { SynthesisConfig } from './config.js'
+
+interface CliDeps {
+  processManager: ProcessManager
+  mapping: SessionMapping
+  config: SynthesisConfig
+}
+
+/**
+ * `openclaw synthesis ...` admin commands. Used to inspect & poke the running
+ * pool from outside (helpful for testing without a real channel inbound).
+ *
+ * Subcommands (planned):
+ *   list                              — show live processes + mapping
+ *   push <session> <text>            — fake an inbound message
+ *   kill <session>                   — terminate a process (mapping preserved)
+ *   forget <session>                 — drop mapping entirely (next msg = new claude session)
+ */
+export function registerCli(api: OpenClawPluginApi, deps: CliDeps): void {
+  // The exact API shape for command registration depends on the OpenClaw
+  // plugin-sdk version. Two common forms seen in existing plugins:
+  //
+  //   api.commands?.register('synthesis', { describe, handler })
+  //   api.cli?.command('synthesis', sub => sub.command('list', '...', () => {...}))
+  //
+  // Both are stubbed below — pick whichever the loaded SDK exposes when
+  // wiring this for real.
+
+  const _ = { api, deps }
+  // TODO: wire actual command registration once the surrounding plugin
+  // patterns are confirmed (see contractor-agent/commands/register-cli.ts
+  // for the canonical example in this codebase).
+  void _
+}