feat(dynamic-tools-cache): 4 cache tools + global __padded API

Implements the openclaw side of Plexum decision #37: agent-driven
per-session whitelist of which tools the model sees. Cross-runtime
aligned with Plexum's host implementation (same tool names, same
input schemas, takes-effect-next-turn).

New surface:
  - tools/dynamic-tools-cache.ts:
      Catalog (in-memory map), Cache file (atomic tmp+rename at
      <openclaw>/agents/<id>/sessions/<sid>/dynamic-tools-cache.json),
      4 tool factories (list/search/cache/evict), allowTool gate,
      installGlobalApi for globalThis.__padded with buffer-drain
  - index.ts: install __padded early; register the 4 cache tools
    as factories wrapping ctx into execute
  - openclaw.plugin.json contracts.tools += 4 names

Other Hangman-Lab plugins (Fabric / HF / Dialectic) opt in to the
gate by wrapping their registerTool calls (separate commits in those
repos). Built-in openclaw tools and non-opt-in plugins remain
always-on.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

plugin/index.ts

@@ -12,6 +12,13 @@ import {
   queueDynamicTrim,
   drainTrimQueueForSession,
 } from './tools/session-rewrite.js';
+import {
+  installGlobalApi as installPaddedGlobalApi,
+  createListToolsTool,
+  createSearchToolsTool,
+  createCacheToolsTool,
+  createEvictToolsTool,
+} from './tools/dynamic-tools-cache.js';
 import {
   safeRestart,
   createSafeRestartTool,
@@ -51,6 +58,12 @@ function register(api: OpenClawPluginApi): void {
 
   logger.info('PaddedCell plugin initializing...');
 
+  // Install globalThis.__padded EARLY so other plugins loaded after
+  // PaddedCell can register catalog entries / query allowTool. Plugins
+  // loaded BEFORE PaddedCell can pre-fill _pendingCatalog on a stub;
+  // installGlobalApi drains it.
+  installPaddedGlobalApi();
+
   const pluginConfig = getPluginConfig(api);
   const openclawPath = resolveOpenclawPath(pluginConfig as { openclawProfilePath?: string });
   const proxyAllowlist = resolveProxyAllowlist(pluginConfig as { proxyAllowlist?: unknown; 'proxy-allowlist'?: unknown });
@@ -241,6 +254,27 @@ function register(api: OpenClawPluginApi): void {
     } as any;
   });
 
+  // dynamic-{list,search,cache,evict}-tools — per-session tools-cache
+  // family (cross-runtime alignment with Plexum decision #37). All four
+  // are essentials (always exposed). The cache they manage gates other
+  // opt-in plugins via globalThis.__padded.allowTool — see
+  // tools/dynamic-tools-cache.ts and plans/OPENCLAW_TOOLS_FILTER_HOOK.md.
+  const cacheToolFactories = [
+    createListToolsTool,
+    createSearchToolsTool,
+    createCacheToolsTool,
+    createEvictToolsTool,
+  ];
+  for (const make of cacheToolFactories) {
+    api.registerTool((ctx) => {
+      const tool = make();
+      const inner = tool.execute;
+      tool.execute = async (callId: string, params: any) =>
+        inner(callId, params, { agentId: ctx.agentId, sessionId: ctx.sessionId });
+      return tool;
+    });
+  }
+
   // Register /ego-mgr slash command if the host exposes the (non-standard) hook.
   // This API is not part of the current OpenClawPluginApi surface; the guard
   // makes the plugin a no-op for slash commands when the host doesn't support