fix(proactive): PROACTIVE=false means no suggestions, including 'want me to run /X?' (W5.1)

The router forbade suggesting skills when PROACTIVE is false while the preamble
told the model to ask 'want me to run it?'. Decision: false means never
auto-invoke and never suggest, including by asking. The preamble line in
generate-upgrade-check.ts now matches the router, and both quote the value
as `false`, the way gstack-skill-start prints it. Restore with
gstack-config set proactive true.

W7a pin: test/gen-skill-docs.test.ts:4488 used the old quoted sentence as a
preamble-order marker; it now finds the PROACTIVE-false rule with a
quote-tolerant, case-insensitive pattern.

SKILL.md.tmpl

@@ -46,9 +46,10 @@ output echoed:
 ~/.claude/skills/gstack/bin/gstack-telemetry-log --event-type route --skill gstack --outcome ROUTE_OUTCOME --session-id "SESSION_ID" 2>/dev/null || true
 ```
 
-If `PROACTIVE` is `false`: do NOT proactively invoke or suggest other gstack skills during
-this session. Only run skills the user explicitly invokes. This preference persists across
-sessions via `gstack-config`.
+If `PROACTIVE` is `false`: do not proactively invoke or suggest other gstack skills during
+this session, including by asking whether to run one ("want me to run /X?"). Only run
+skills the user explicitly invokes. This preference persists across sessions via
+`gstack-config`.
 
 If `PROACTIVE` is `true` (default): **invoke the Skill tool** when the user's request
 matches a skill's purpose. Do NOT answer directly when a skill exists for the task.

scripts/resolvers/preamble/generate-upgrade-check.ts

@@ -8,7 +8,7 @@ import type { TemplateContext } from '../types';
  * the fence prose scopes and the model follows.
  */
 export function generateUpgradeCheck(ctx: TemplateContext): string {
-  return `If \`PROACTIVE\` is \`"false"\`, do not auto-invoke or proactively suggest skills. If a skill seems useful, ask: "I think /skillname might help here — want me to run it?"
+  return `If \`PROACTIVE\` is \`false\`, do not auto-invoke or suggest skills, including by asking whether to run one. Only run skills the user explicitly invokes.
 
 If \`SKILL_PREFIX\` is \`"true"\`, suggest/invoke \`/gstack-*\` names. Disk paths stay \`${ctx.paths.skillRoot}/[skill-name]/SKILL.md\`.`;
 }

test/gen-skill-docs.test.ts

@@ -4485,7 +4485,7 @@ describe('plan-mode-info resolver (handshake-replacement)', () => {
       'utf-8',
     );
     const planModeIdx = content.indexOf(PLAN_MODE_INFO_MARKER);
-    const upgradeIdx = content.indexOf('If `PROACTIVE` is `"false"`');
+    const upgradeIdx = content.search(/If `PROACTIVE` is `"?false"?`/i);
     expect(planModeIdx).toBeGreaterThan(0);
     expect(upgradeIdx).toBeGreaterThan(0);
     expect(planModeIdx).toBeLessThan(upgradeIdx);