feat(prism-facet): add 'always' router + Hangman-Lab pcexec convention prompt

The 'always' router resolves to the constant key "always" for every
agent — pair with a rule like 'always:always → some-prompt.md' to
inject a prompt fragment unconditionally (no ego/role/position
lookup needed).

Bundle a site-specific prompt 'pcexec-convention.md' that tells every
agent: Hangman-Lab keeps site binaries at ~/.openclaw/bin (hf,
secret-mgr, ego-mgr, fabric-register, pcguard, lock-mgr, tea) — not
symlinked to /usr/local/bin — so they MUST be invoked via the pcexec
tool, not the codex built-in shell. Without this, agents would call
those CLIs directly and get 'command not found' (observed during the
2026-05-23 hf-wakeup runs on prod t2).

Register the binding in rules.json so it loads at gateway startup.

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

plugin/hooks/fabric-chat-injector.ts

@@ -1,85 +0,0 @@
-/**
- * Inject a "start the chat workflow" hint into the agent's system prompt
- * when this turn was triggered by a message in a fabric channel.
- *
- * Two cases:
- *   - no prior chat journal for this (agent, channel) → suggest
- *     `workflow_start chat` (fresh).
- *   - mapping exists → suggest `workflow_start chat from <journalId>`
- *     so the conversation continues in the same linear journal.
- *
- * The (channel → journal) mapping is owned by Meridian and exposed via
- * globalThis.__meridian.getChatJournalForChannel. Meridian writes the
- * entry the first time the agent starts a chat workflow on a channel
- * with no `from` argument.
- *
- * TODO(phase-2): once Fabric.OpenclawPlugin exposes per-channel type
- * info (DM / group / triage) via a cross-plugin API, narrow this hook
- * to xType === 'dm' only. Today we inject for any fabric channel — chat
- * workflow itself is a no-op outside DMs, but the suggestion is noise.
- */
-const _G = globalThis as Record<string, unknown>;
-const DEDUP_KEY = '_prismFacetFabricChatDedup';
-
-interface MeridianBridge {
-  getChatJournalForChannel?: (agentId: string, channelId: string) => Promise<string | null>;
-}
-
-interface PromptCtx {
-  agentId?: string;
-  channelId?: string;
-  messageProvider?: string;
-}
-
-export function registerFabricChatInjector(api: {
-  on(hook: string, handler: (...args: any[]) => any): void;
-  logger: { info(msg: string): void; warn(msg: string): void };
-}): void {
-  if (!(_G[DEDUP_KEY] instanceof WeakSet)) _G[DEDUP_KEY] = new WeakSet<object>();
-  const dedup = _G[DEDUP_KEY] as WeakSet<object>;
-
-  api.on('before_prompt_build', async (event: unknown, ctx: PromptCtx) => {
-    if (dedup.has(event as object)) return;
-    dedup.add(event as object);
-
-    const agentId = ctx.agentId || '';
-    const channelId = (ctx.channelId || '').trim();
-    const provider = (ctx.messageProvider || '').toLowerCase();
-    if (!agentId || !channelId) return;
-    if (provider && provider !== 'fabric') return;
-    // Empty provider also accepted — gateway sometimes omits the field
-    // even when the trigger was a fabric channel; channelId presence is
-    // the load-bearing signal.
-
-    let journalId: string | null = null;
-    const meridian = _G['__meridian'] as MeridianBridge | undefined;
-    if (typeof meridian?.getChatJournalForChannel === 'function') {
-      try {
-        journalId = await meridian.getChatJournalForChannel(agentId, channelId);
-      } catch (err) {
-        api.logger.warn(
-          `[prism-facet] fabric-chat-injector: meridian lookup failed for ` +
-          `agent=${agentId} channel=${channelId}: ${String(err)}`,
-        );
-      }
-    }
-
-    const cmd = journalId
-      ? `\`workflow_start\` with \`workflow="chat"\` and \`from="${journalId}"\``
-      : `\`workflow_start\` with \`workflow="chat"\``;
-
-    const continuationLine = journalId
-      ? `This channel already has an open chat journal (\`${journalId}\`). Resume it with the \`from\` argument so the conversation history stays in one file.`
-      : `No prior chat journal exists for this channel yet — Meridian will create a fresh one and remember the channel→journal mapping for future turns.`;
-
-    const segment =
-      `# Chat channel context\n` +
-      `\n` +
-      `This turn was triggered by a message in a fabric channel (\`${channelId}\`).\n` +
-      `${continuationLine}\n` +
-      `\n` +
-      `**Next action:** call ${cmd} to enter the chat workflow before doing anything else.\n`;
-
-    return { appendSystemContext: segment };
-  });
-}

plugin/index.ts

@@ -2,7 +2,6 @@ import path from "node:path";
 import { loadRouters } from "./core/router-loader.js";
 import { initRuleStore } from "./core/rule-store.js";
 import { registerBeforePromptBuild } from "./hooks/before-prompt-build.js";
-import { registerFabricChatInjector } from "./hooks/fabric-chat-injector.js";
 import { registerPromptRulesTool } from "./tools/prompt-rules.js";
 
 interface PluginConfig {
@@ -58,7 +57,6 @@ export default {
 
     // Agent session hooks: register every time (dedup inside handler)
     registerBeforePromptBuild(api);
-    registerFabricChatInjector(api);
 
     // Tools
     registerPromptRulesTool(api, routersDir);