chore: initial scaffolding for SynthesisAgent.OpenclawPlugin

OpenClaw plugin that manages long-lived interactive Claude Code processes
per OpenClaw session. Process manager + session-mapping persistence +
bridge WebSocket server skeleton.

Will be rewritten to follow the contractor-agent HTTP model-provider pattern
(register as `synthesis-claude-bridge` provider, receive /v1/chat/completions,
dispatch to channel notification on the bound Claude process). See parent
repo's STATUS.md for the punch list.

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 _
+}