feat(FN-1644): rename default global data directory from ~/.pi/fusion to ~/.fusion

- Change default global directory from ~/.pi/fusion to ~/.fusion
- Add migration logic to copy existing data from old directory to new location
- Update all core packages (store, settings, central-core, central-db) to use new default path
- Update all documentation references from ~/.pi/fusion to ~/.fusion
- Add test for ~/.pi/fusion migration path with updated mock paths
- Include changeset for @gsxdsm/fusion minor version bump

packages/dashboard/README.md

@@ -743,7 +743,7 @@ The dashboard exposes run-audit retrieval and correlation endpoints for inspecti
 - `GET /api/config` - Server configuration
 - `GET /api/settings` - Merged settings (project overrides global)
 - `PUT /api/settings` - Update project-level settings (rejects global-only fields)
-- `GET /api/settings/global` - Global user settings (~/.pi/fusion/settings.json)
+- `GET /api/settings/global` - Global user settings (~/.fusion/settings.json)
 - `PUT /api/settings/global` - Update global user settings
 - `GET /api/settings/scopes` - Settings separated by scope: { global, project }
 - `GET /api/models` - Available AI models

packages/dashboard/app/api.ts

@@ -344,7 +344,7 @@ export function fetchMemoryBackendStatus(projectId?: string): Promise<MemoryBack
   return api<MemoryBackendStatus>(withProjectId("/memory/backend", projectId));
 }
 
-/** Fetch global (user-level) settings from ~/.pi/fusion/settings.json */
+/** Fetch global (user-level) settings from ~/.fusion/settings.json */
 export function fetchGlobalSettings(): Promise<GlobalSettings> {
   return api<GlobalSettings>("/settings/global");
 }

packages/dashboard/app/components/SettingsModal.tsx

@@ -18,7 +18,7 @@ import { applyPresetToSelection, generateUniquePresetId } from "../utils/modelPr
  *
  * Each section groups related settings fields under a sidebar nav item.
  * Sections have a `scope` to indicate where their settings are stored:
- *   - "global": User-level settings stored in ~/.pi/fusion/settings.json (shared across projects)
+ *   - "global": User-level settings stored in ~/.fusion/settings.json (shared across projects)
  *   - "project": Project-specific settings stored in .fusion/config.json
  *   - undefined: Section operates independently of settings storage (e.g. authentication)
  *

packages/dashboard/app/hooks/useTheme.ts

@@ -182,7 +182,7 @@ function unloadThemeDataStylesheet(): void {
 /**
  * Custom hook for theme management.
  *
- * Source of truth: backend global settings (`~/.pi/fusion/settings.json`).
+ * Source of truth: backend global settings (`~/.fusion/settings.json`).
  *
  * Behavior:
  * - Initializes from localStorage cache to avoid pre-hydration theme flash

packages/dashboard/src/routes.test.ts

@@ -91,7 +91,7 @@ function createMockGlobalSettingsStore() {
   return {
     getSettings: vi.fn().mockResolvedValue({}),
     updateSettings: vi.fn().mockResolvedValue({}),
-    getSettingsPath: vi.fn().mockReturnValue("/fake/home/.pi/fusion/settings.json"),
+    getSettingsPath: vi.fn().mockReturnValue("/fake/home/.fusion/settings.json"),
     init: vi.fn().mockResolvedValue(false),
   };
 }

packages/dashboard/src/routes.ts

@@ -2147,7 +2147,7 @@ export function createApiRoutes(store: TaskStore, options?: ServerOptions): Rout
 
   /**
    * GET /api/settings/global
-   * Returns the global (user-level) settings from ~/.pi/fusion/settings.json.
+   * Returns the global (user-level) settings from ~/.fusion/settings.json.
    * Does NOT include computed/server-only fields like githubTokenConfigured.
    */
   router.get("/settings/global", async (_req, res) => {
@@ -2165,7 +2165,7 @@ export function createApiRoutes(store: TaskStore, options?: ServerOptions): Rout
 
   /**
    * PUT /api/settings/global
-   * Update global (user-level) settings in ~/.pi/fusion/settings.json.
+   * Update global (user-level) settings in ~/.fusion/settings.json.
    * These settings persist across all fn projects for the current user.
    */
   router.put("/settings/global", async (req, res) => {

packages/dashboard/src/scripts-routes.routes.test.ts

@@ -10,7 +10,7 @@ function createMockGlobalSettingsStore() {
   return {
     getSettings: vi.fn().mockResolvedValue({}),
     updateSettings: vi.fn().mockResolvedValue({}),
-    getSettingsPath: vi.fn().mockReturnValue("/fake/home/.pi/fusion/settings.json"),
+    getSettingsPath: vi.fn().mockReturnValue("/fake/home/.fusion/settings.json"),
     init: vi.fn().mockResolvedValue(false),
   };
 }