fix(FN-1952): restore pi auth and extension loading

packages/engine/src/auth-storage.ts

@@ -22,6 +22,10 @@ export function getFusionAuthPath(home = getHomeDir()): string {
   return join(home, ".fusion", "agent", "auth.json");
 }
 
+export function getFusionModelsPath(home = getHomeDir()): string {
+  return join(home, ".fusion", "agent", "models.json");
+}
+
 function getLegacyAuthPaths(home = getHomeDir()): string[] {
   return [
     join(home, ".pi", "agent", "auth.json"),
@@ -29,6 +33,22 @@ function getLegacyAuthPaths(home = getHomeDir()): string[] {
   ];
 }
 
+function getLegacyModelsPaths(home = getHomeDir()): string[] {
+  return [
+    join(home, ".pi", "agent", "models.json"),
+    join(home, ".pi", "models.json"),
+  ];
+}
+
+export function getModelRegistryModelsPath(home = getHomeDir()): string {
+  const fusionModelsPath = getFusionModelsPath(home);
+  if (existsSync(fusionModelsPath)) {
+    return fusionModelsPath;
+  }
+
+  return getLegacyModelsPaths(home).find((modelsPath) => existsSync(modelsPath)) ?? fusionModelsPath;
+}
+
 function readLegacyCredentials(authPaths = getLegacyAuthPaths()): Record<string, StoredCredential> {
   const credentials: Record<string, StoredCredential> = {};
 

packages/engine/src/executor.ts

@@ -13,7 +13,7 @@ import { Type, type Static } from "@mariozechner/pi-ai";
 import { createKbAgent, describeModel, promptWithFallback, compactSessionContext } from "./pi.js";
 import { buildSessionSkillContext } from "./session-skill-context.js";
 import { reviewStep, type ReviewVerdict } from "./reviewer.js";
-import { ModelRegistry, SessionManager, getAgentDir, type ToolDefinition, type AgentSession } from "@mariozechner/pi-coding-agent";
+import { ModelRegistry, SessionManager, type ToolDefinition, type AgentSession } from "@mariozechner/pi-coding-agent";
 import { PRIORITY_EXECUTE, type AgentSemaphore } from "./concurrency.js";
 import { isRegisteredGitWorktree, isUsableTaskWorktree, type WorktreePool } from "./worktree-pool.js";
 import { AgentLogger } from "./agent-logger.js";
@@ -42,7 +42,7 @@ import {
   createTaskLogTool as sharedCreateTaskLogTool,
 } from "./agent-tools.js";
 import { getTaskCompletionBlockerForStore } from "./task-completion.js";
-import { createFusionAuthStorage } from "./auth-storage.js";
+import { createFusionAuthStorage, getModelRegistryModelsPath } from "./auth-storage.js";
 
 // Re-export for backward compatibility (tests import from executor.ts)
 export { summarizeToolArgs } from "./agent-logger.js";
@@ -392,7 +392,7 @@ export class TaskExecutor {
   private get modelRegistry(): InstanceType<typeof ModelRegistry> {
     if (!this._modelRegistry) {
       const authStorage = createFusionAuthStorage();
-      this._modelRegistry = new ModelRegistry(authStorage, join(getAgentDir(), "models.json"));
+      this._modelRegistry = new ModelRegistry(authStorage, getModelRegistryModelsPath());
       this._modelRegistry.refresh();
     }
     return this._modelRegistry;

packages/engine/src/pi-create-kb-agent.test.ts

@@ -422,7 +422,11 @@ describe("createKbAgent", () => {
       defaultModelId: "glm-5.1",
     });
 
-    expect(discoverAndLoadExtensionsMock).toHaveBeenCalledWith(["/extensions/zai-provider"], "/tmp", undefined);
+    expect(discoverAndLoadExtensionsMock).toHaveBeenCalledWith(
+      ["/extensions/zai-provider"],
+      "/tmp",
+      "/tmp/.fusion/disabled-auto-extension-discovery",
+    );
     expect(registerProviderMock).toHaveBeenCalledWith("zai", expect.objectContaining({
       models: [{ id: "glm-5.1" }],
     }));

packages/engine/src/pi.ts

@@ -20,20 +20,20 @@ import {
   DefaultResourceLoader,
   DefaultPackageManager,
   discoverAndLoadExtensions,
-  getAgentDir,
   ModelRegistry,
   SessionManager,
   SettingsManager,
   type AgentSession,
   type ToolDefinition,
 } from "@mariozechner/pi-coding-agent";
+import { getEnabledPiExtensionPaths, getFusionAgentDir, getLegacyPiAgentDir, resolvePiExtensionProjectRoot } from "@fusion/core";
 import {
   resolveSessionSkills,
   createSkillsOverrideFromSelection,
   type SkillSelectionContext,
 } from "./skill-resolver.js";
 import { isContextLimitError } from "./context-limit-detector.js";
-import { createFusionAuthStorage } from "./auth-storage.js";
+import { createFusionAuthStorage, getModelRegistryModelsPath } from "./auth-storage.js";
 
 export interface AgentResult {
   session: AgentSession;
@@ -252,8 +252,9 @@ function readJsonObject(path: string): Record<string, any> {
 }
 
 function createReadOnlyPiSettingsView(cwd: string, agentDir: string): PackageManagerSettingsView {
+  const projectRoot = resolvePiExtensionProjectRoot(cwd);
   const globalSettings = readJsonObject(join(agentDir, "settings.json"));
-  const fusionProjectSettings = readJsonObject(join(cwd, ".fusion", "settings.json"));
+  const fusionProjectSettings = readJsonObject(join(projectRoot, ".fusion", "settings.json"));
   const mergedSettings = { ...globalSettings, ...fusionProjectSettings };
 
   return {
@@ -265,9 +266,22 @@ function createReadOnlyPiSettingsView(cwd: string, agentDir: string): PackageMan
   };
 }
 
+function getPackageManagerAgentDir(): string {
+  const fusionAgentDir = getFusionAgentDir();
+  if (
+    existsSync(join(fusionAgentDir, "settings.json")) ||
+    existsSync(join(fusionAgentDir, "extensions"))
+  ) {
+    return fusionAgentDir;
+  }
+
+  const legacyAgentDir = getLegacyPiAgentDir();
+  return existsSync(legacyAgentDir) ? legacyAgentDir : fusionAgentDir;
+}
+
 async function registerExtensionProviders(cwd: string, modelRegistry: ModelRegistry): Promise<void> {
   try {
-    const agentDir = getAgentDir();
+    const agentDir = getPackageManagerAgentDir();
     const packageManager = new DefaultPackageManager({
       cwd,
       agentDir,
@@ -278,7 +292,11 @@ async function registerExtensionProviders(cwd: string, modelRegistry: ModelRegis
       .filter((resource) => resource.enabled)
       .map((resource) => resource.path);
 
-    const extensionsResult = await discoverAndLoadExtensions(packageExtensionPaths, cwd, undefined);
+    const extensionsResult = await discoverAndLoadExtensions(
+      [...getEnabledPiExtensionPaths(cwd), ...packageExtensionPaths],
+      cwd,
+      join(resolvePiExtensionProjectRoot(cwd), ".fusion", "disabled-auto-extension-discovery"),
+    );
 
     for (const { path, error } of extensionsResult.errors) {
       console.error(`[extensions] Failed to load ${path}: ${error}`);
@@ -475,7 +493,7 @@ export function wrapToolsWithBoundary(
 export async function createKbAgent(options: AgentOptions): Promise<AgentResult> {
   console.error(`[pi] createKbAgent called (cwd=${options.cwd}, tools=${options.tools}, provider=${options.defaultProvider}, model=${options.defaultModelId})`);
   const authStorage = createFusionAuthStorage();
-  const modelRegistry = new ModelRegistry(authStorage, join(getAgentDir(), "models.json"));
+  const modelRegistry = new ModelRegistry(authStorage, getModelRegistryModelsPath());
   await registerExtensionProviders(options.cwd, modelRegistry);
 
   const tools =

packages/engine/src/project-manager.ts

@@ -97,6 +97,7 @@ export class ProjectManager extends EventEmitter<ProjectManagerEvents> {
   private globalSemaphore: AgentSemaphore;
   /** Mutable limit read by the shared semaphore's getter function. */
   private currentGlobalLimit = 4;
+  private globalLimitRefreshInterval: ReturnType<typeof setInterval>;
 
   /**
    * @param centralCore - CentralCore reference for global coordination
@@ -112,7 +113,8 @@ export class ProjectManager extends EventEmitter<ProjectManagerEvents> {
 
     // Refresh the global limit periodically
     this.refreshGlobalLimit();
-    setInterval(() => this.refreshGlobalLimit(), 30000); // Refresh every 30s
+    this.globalLimitRefreshInterval = setInterval(() => this.refreshGlobalLimit(), 30000);
+    this.globalLimitRefreshInterval.unref?.();
 
     projectManagerLog.log("ProjectManager initialized");
   }
@@ -475,6 +477,7 @@ export class ProjectManager extends EventEmitter<ProjectManagerEvents> {
 
     await Promise.all(stopPromises);
 
+    clearInterval(this.globalLimitRefreshInterval);
     projectManagerLog.log("All project runtimes stopped");
     this.removeAllListeners();
   }