feat(skills): third-party web-actions contract — offer to drive vendor-site steps, never just dump a manual list

When a workflow needs something done on an external website the user
controls (register an API key, create a vendor account, configure a
dashboard/webhook/OAuth app), five skills (ship, spec, office-hours,
setup-deploy, land-and-deploy) now follow one contract: offer to drive it
in a visible browser via gstack's own stack ($B headed + handoff/resume,
GStack Browser) behind ONE per-task consent question naming the exact site
and actions; passwords, payment, CAPTCHA, and identity stay user-performed;
captured secrets go to owner-only files or the user's secret store, never
chat/logs/history; and the credential is verified with one non-mutating API
call before any success claim — dashboards show masked placeholders, and a
401 catches them. Declining yields manual steps and a blocked-on-user mark;
nothing new is ever installed to close the gap.

New resolver token {{THIRD_PARTY_ACTIONS}} (adapted from the fork's
contract — their Aside-browser detection swapped for our own driver stack;
MIT portions noted). Parity guards bumped with growth itemized (ship
1.10->1.12 at measured 1.103x; office-hours skeleton 101K / 1.09 at
measured 1.079x); ship goldens refreshed.

Ported from time-attack/gstack (GStack 2), driver adaptation ours.

Co-authored-by: Sina Matian <sina@time-attack.dev>
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

scripts/resolvers/index.ts

@@ -36,12 +36,14 @@ import { generateMakePdfSetup } from './make-pdf';
 import { generateTasksSectionEmit, generateTasksSectionAggregate } from './tasks-section';
 import { SECTION, SECTION_INDEX } from './sections';
 import { generateRedactTaxonomyTable, generateRedactInvocationBlock } from './redact-doc';
+import { generateThirdPartyActions } from './third-party-actions';
 
 export const RESOLVERS: Record<string, ResolverValue> = {
   SLUG_EVAL: generateSlugEval,
   SLUG_SETUP: generateSlugSetup,
   REDACT_TAXONOMY_TABLE: generateRedactTaxonomyTable,
   REDACT_INVOCATION_BLOCK: generateRedactInvocationBlock,
+  THIRD_PARTY_ACTIONS: generateThirdPartyActions,
   COMMAND_REFERENCE: generateCommandReference,
   SNAPSHOT_FLAGS: generateSnapshotFlags,
   PREAMBLE: generatePreamble,

scripts/resolvers/third-party-actions.ts

@@ -0,0 +1,33 @@
+/**
+ * {{THIRD_PARTY_ACTIONS}} — the third-party web actions contract.
+ *
+ * Governs the moment a workflow needs something done on an external website
+ * the user controls: registering an API key, creating a vendor account,
+ * configuring a dashboard, webhook, OAuth app, billing plan, or domain
+ * verification. Instead of dumping a manual step list, the skill offers to
+ * drive the browser (consent-gated, secrets never in chat) and verifies the
+ * captured credential before claiming success.
+ *
+ * Adapted from time-attack/gstack's THIRD-PARTY-ACTIONS.md (GStack 2, MIT):
+ * the fork detected the Aside AI browser; we drive our own stack — browse
+ * headed mode + handoff/resume ($B), GStack Browser, and pair-agent.
+ * Portions copyright (c) 2026 Sina Matian, time-attack/gstack, MIT.
+ */
+
+import type { TemplateContext } from './types';
+
+export function generateThirdPartyActions(_ctx: TemplateContext): string {
+  return `## Third-Party Web Actions
+
+A step sometimes requires action on an external website the user controls: registering an API key, creating a vendor or developer account, configuring a dashboard, webhook, OAuth app, billing plan, or domain verification. This contract governs that moment. It grants no new browsing authority — the AskUserQuestion format and one-way-door rules remain binding, including approval before anything that spends money.
+
+1. **Never hand the user a manual step list for a third-party site without first offering to drive it.** The driver is gstack's own browser stack: \`$B\` headed mode with handoff/resume for the human-only moments (see the /browse skill), or GStack Browser when installed. Never install new tooling to close the gap, and never treat tooling presence as consent to browse.
+
+2. **One explicit question before any browsing.** STOP and name the exact site and the exact actions (for example "create a test-mode API token in the Duffel dashboard"), then offer: A) I drive it now in a visible browser — you take over for sign-in and approvals, B) manual instructions, C) defer. The selection is per-task consent; never persist it as standing permission and never infer it from an earlier task.
+
+3. **When driving, touch only the named site and actions.** Password entry, new-account credential choice, payment, CAPTCHA, and identity verification are user-performed: hand off (\`$B handoff\`) and wait instead of acting. Prefer credential flows that never expose the secret to the agent, such as password-manager autofill or the dashboard's own copy button used by the human.
+
+4. **A captured secret never appears in chat output, logs, or shell history.** Write it to a user-approved local file with owner-only permissions (0600) or the user's secret store, and keep generated destinations out of version control. Dashboard fields are often masked placeholders — verify the captured credential with ONE non-mutating API call before claiming success; a 401 here has caught a placeholder masquerading as a key.
+
+5. **If the user declines or defers, or no browser is usable,** provide the manual steps and mark the step blocked on the user. Do not recommend or install new products to close the gap.`;
+}