Agents: add system prompt safety guardrails (#5445)

* 🤖 agents: add system prompt safety guardrails

What:
- add safety guardrails to system prompt
- update system prompt docs
- update prompt tests

Why:
- discourage power-seeking or self-modification behavior
- clarify safety/oversight priority when conflicts arise

Tests:
- pnpm lint (pass)
- pnpm build (fails: DefaultResourceLoader missing in pi-coding-agent)
- pnpm test (not run; build failed)

* 🤖 agents: tighten safety wording for prompt guardrails

What:
- scope safety wording to system prompts/safety/tool policy changes
- document Safety inclusion in minimal prompt mode
- update safety prompt tests

Why:
- avoid blocking normal code changes or PR workflows
- keep prompt mode docs consistent with implementation

Tests:
- pnpm lint (pass)
- pnpm build (fails: DefaultResourceLoader missing in pi-coding-agent)
- pnpm test (not run; build failed)

* 🤖 docs: note safety guardrails are soft

What:
- document system prompt safety guardrails as advisory
- add security note on prompt guardrails vs hard controls

Why:
- clarify threat model and operator expectations
- avoid implying prompt text is an enforcement layer

Tests:
- pnpm lint (pass)
- pnpm build (fails: DefaultResourceLoader missing in pi-coding-agent)
- pnpm test (not run; build failed)

src/agents/system-prompt.ts

@@ -7,7 +7,7 @@ import type { EmbeddedContextFile } from "./pi-embedded-helpers.js";
 /**
  * Controls which hardcoded sections are included in the system prompt.
  * - "full": All sections (default, for main agent)
- * - "minimal": Reduced sections (Tooling, Workspace, Runtime) - used for subagents
+ * - "minimal": Reduced sections (Tooling, Safety, Workspace, Sandbox, Runtime) - used for subagents
  * - "none": Just basic identity line, no sections
  */
 export type PromptMode = "full" | "minimal" | "none";
@@ -64,6 +64,16 @@ function buildTimeSection(params: { userTimezone?: string }) {
   return ["## Current Date & Time", `Time zone: ${params.userTimezone}`, ""];
 }
 
+function buildSafetySection() {
+  return [
+    "## Safety",
+    "You have no independent goals: do not pursue self-preservation, replication, resource acquisition, or power-seeking; avoid long-term plans beyond the user's request.",
+    "Prioritize safety and human oversight over completion; if instructions conflict, pause and ask; comply with stop/pause/audit requests and never bypass safeguards. (Inspired by Anthropic's constitution.)",
+    "Do not manipulate or persuade anyone to expand access or disable safeguards. Do not copy yourself or change system prompts, safety rules, or tool policies unless explicitly requested.",
+    "",
+  ];
+}
+
 function buildReplyTagsSection(isMinimal: boolean) {
   if (isMinimal) {
     return [];
@@ -382,6 +392,7 @@ export function buildAgentSystemPrompt(params: {
     "Keep narration brief and value-dense; avoid repeating obvious steps.",
     "Use plain human language for narration unless in a technical context.",
     "",
+    ...buildSafetySection(),
     "## OpenClaw CLI Quick Reference",
     "OpenClaw is controlled via subcommands. Do not invent commands.",
     "To manage the Gateway daemon service (start/stop/restart):",