feat: OpenClaw integration — gstack-lite/full generation + spawned session detection

Add includeSkills filter to gen-skill-docs pipeline. Generate gstack-lite
(planning discipline for spawned coding sessions) and gstack-full (complete
feature pipeline) for OpenClaw host. Add OPENCLAW_SESSION env var detection
in preamble for spawned session auto-detect. Update setup --host openclaw
to print redirect message.

scripts/resolvers/preamble.ts

@@ -89,6 +89,8 @@ fi
 _ROUTING_DECLINED=$(${ctx.paths.binDir}/gstack-config get routing_declined 2>/dev/null || echo "false")
 echo "HAS_ROUTING: $_HAS_ROUTING"
 echo "ROUTING_DECLINED: $_ROUTING_DECLINED"
+# Detect spawned session (OpenClaw or other orchestrator)
+[ -n "$OPENCLAW_SESSION" ] && echo "SPAWNED_SESSION: true" || true
 \`\`\``;
 }
 
@@ -226,6 +228,15 @@ Say "No problem. You can add routing rules later by running \`gstack-config set
 This only happens once per project. If \`HAS_ROUTING\` is \`yes\` or \`ROUTING_DECLINED\` is \`true\`, skip this entirely.`;
 }
 
+function generateSpawnedSessionCheck(): string {
+  return `If \`SPAWNED_SESSION\` is \`"true"\`, you are running inside a session spawned by an
+AI orchestrator (e.g., OpenClaw/Wintermute). In spawned sessions:
+- Do NOT use AskUserQuestion for interactive prompts. Auto-choose the recommended option.
+- Do NOT run upgrade checks, telemetry prompts, routing injection, or lake intro.
+- Focus on completing the task and reporting results via prose output.
+- End with a completion report: what shipped, decisions made, anything uncertain.`;
+}
+
 function generateAskUserFormat(_ctx: TemplateContext): string {
   return `## AskUserQuestion Format
 
@@ -675,6 +686,7 @@ export function generatePreamble(ctx: TemplateContext): string {
     generateTelemetryPrompt(ctx),
     generateProactivePrompt(ctx),
     generateRoutingInjection(ctx),
+    generateSpawnedSessionCheck(),
     generateVoiceDirective(tier),
     ...(tier >= 2 ? [generateContextRecovery(ctx), generateAskUserFormat(ctx), generateCompletenessSection()] : []),
     ...(tier >= 3 ? [generateRepoModeSection(), generateSearchBeforeBuildingSection(ctx)] : []),