refactor(plugin): fabric-register is a script, not a tool

Binding an agent's Fabric API key was an OpenClaw tool; make it a
self-contained Node script installed to ~/.openclaw/bin/fabric-register
instead.

- bin/fabric-register.mjs: no plugin deps; AGENT_ID env wins, else
  --agent-id required; --api-key validated via POST /auth/agent/login;
  on success upserts ~/.openclaw/fabric-identity.json (format matches
  IdentityRegistry). Flags/env for center, identity-file, openclaw-path.
- install.mjs: copy the script to ~/.openclaw/bin (chmod 0755) on
  install, remove on uninstall; Next-steps updated.
- tools.ts: drop the fabric-register tool; ctxGuild error now points to
  the script / static accounts config.
- README updated.

Verified: missing-id -> exit 2; --agent-id and AGENT_ID both bind and
write a valid identity file; bad key -> 401, no write.

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

src/tools.ts

@@ -25,7 +25,12 @@ export function registerFabricTools(
   // Resolve the calling agent's Fabric session + a guild's token/endpoint.
   const ctxGuild = async (agentId: string, guildNodeId: string) => {
     const entry = identity.findByAgentId(agentId);
-    if (!entry) throw new Error(`agent ${agentId} not registered (call fabric-register)`);
+    if (!entry)
+      throw new Error(
+        `agent ${agentId} not registered — run: AGENT_ID=${agentId} ` +
+          `~/.openclaw/bin/fabric-register --api-key <fak_…> (or set ` +
+          `channels.fabric.accounts.${agentId}); then restart the gateway`,
+      );
     const session = await client.agentLogin(entry.fabricApiKey);
     const guild = session.guilds.find((g) => g.nodeId === guildNodeId);
     const token = session.guildAccessTokens.find((t) => t.guildNodeId === guildNodeId)?.token;
@@ -33,31 +38,10 @@ export function registerFabricTools(
     return { session, guild, token };
   };
 
-  // fabric-register: bind this agent to a Fabric API key.
-  api.registerTool((ctx: Ctx) => ({
-    name: 'fabric-register',
-    description: "Register this agent's Fabric API key (minted via Center CLI `user apikey`).",
-    parameters: {
-      type: 'object',
-      additionalProperties: false,
-      required: ['fabricApiKey'],
-      properties: {
-        fabricApiKey: { type: 'string', description: 'Fabric Center API key (fak_…)' },
-      },
-    },
-    execute: async (params: { fabricApiKey: string }) => {
-      const agentId = ctx.agentId;
-      if (!agentId) return { ok: false, error: 'no agent context' };
-      const session = await client.agentLogin(params.fabricApiKey);
-      identity.upsert({
-        agentId,
-        fabricApiKey: params.fabricApiKey,
-        fabricUserId: session.user.id,
-        displayName: session.user.name,
-      });
-      return { ok: true, user: session.user };
-    },
-  }));
+  // NOTE: binding an agent's Fabric API key is intentionally NOT a tool.
+  // It's a one-time step done out-of-band via the installed script
+  //   ~/.openclaw/bin/fabric-register --api-key <fak_…>   (AGENT_ID or --agent-id)
+  // or via static config (channels.fabric.accounts.<agentId>).
 
   const makeCreate = (kind: 'chat' | 'work' | 'report' | 'discussion') =>
     api.registerTool((ctx: Ctx) => ({