Wire Pi candidate into verified installation and provider packs

Co-Authored-By: Paperclip <noreply@paperclip.ing>

packages/paperclip-runner/scripts/candidate-provider-pack.mjs

@@ -1,3 +1,4 @@
+import { materializePiDistribution } from "./materialize-pi-distribution.mjs";
 const CANDIDATES = new Set(["cursor", "copilot", "pi"]);
 
 export function parseProviderPackArguments(args) {
@@ -18,5 +19,6 @@ export function parseProviderPackArguments(args) {
 /** Closed source-owned builder registry; provider branches add their exact pins. */
 export async function materializeCandidateProviderPack({ provider, outputRoot }) {
   if (!CANDIDATES.has(provider)) throw new Error("Unknown candidate provider");
+  if (provider === "pi") return materializePiDistribution({ outputRoot });
   throw new Error(`The ${provider} candidate distribution builder is not included in this source revision`);
 }

packages/paperclip-runner/src/drivers/acpx/profile-installation.ts

@@ -1,8 +1,10 @@
+import { verifyPiInstallation } from "./pi-installation.js";
 import type { QualifiedAcpxAgent, QualifiedAcpxProfile } from "./qualified-profiles.js";
 import { verifyQualifiedAcpxInstallation, type VerifiedAcpxInstallation } from "./installation-integrity.js";
 
 /** Closed build-owned registry. Provider branches add their pinned installations here. */
 export async function verifyAcpxProfileInstallation(profile: QualifiedAcpxProfile): Promise<VerifiedAcpxInstallation> {
+  if (profile.agent === "pi") return verifyPiInstallation(profile);
   if (profile.agent !== "claude" && profile.agent !== "codex" && profile.agent !== "grok") {
     throw new Error(`ACPX ${profile.agent} verified candidate distribution is not installed in this build`);
   }

packages/paperclip-runner/src/drivers/acpx/runtime-host.test.ts

@@ -819,9 +819,6 @@ describe("ACPX runtime host", () => {
     });
     const options = { ...fixture.options, agent: "pi" as const, model,
       permissionMode: "approve-all" as const, providerPolicy: { readOnly: true }, systemInstructions: "Bound instructions" };
-    await expect(AcpxRuntimeHost.open(options, { openRuntime, reportRetainedCleanupFailure: vi.fn() }))
-      .rejects.toThrow("verified candidate distribution is not installed");
-    expect(openRuntime).not.toHaveBeenCalled();
     const host = await AcpxRuntimeHost.open(options, fixture.dependencies({
       verifyInstallation: async () => ({ commandDigest: profile.commandDigest,
         agentServerPackageJsonPath: join(fixture.root, "package.json"), agentRuntimePackageJsonPath: null,