FN-5805: add fn onboard command with sequential runOnboard flow

Add a new interactive onboarding CLI flow that guides first-time setup end to end.

- add new `fn onboard` command wiring in CLI entrypoint and usage help
- implement `runOnboard()` with sequential prompts for central DB, provider auth, init, test mode, and project maxConcurrent
- persist `cliOnboardingCompletedAt` marker in global settings with `--force` rerun support
- add onboarding command tests and global settings regression coverage
- document `fn onboard` usage and options in CLI reference
- add a minor changeset for published `@runfusion/fusion`

Files changed:
 .changeset/fn-5805-onboard-command.md              |   5 +
 docs/cli-reference.md                              |  20 ++
 packages/cli/src/bin.ts                            |  10 +
 packages/cli/src/commands/__tests__/onboard.test.ts| 193 ++++++++++++++++
 packages/cli/src/commands/onboard.ts               | 249 +++++++++++++++++++++
 packages/core/src/__tests__/global-settings.test.ts|  11 +
 packages/core/src/index.ts                         |   2 +-
 packages/core/src/settings-schema.ts               |   1 +
 packages/core/src/types.ts                         |   4 +
 9 files changed, 494 insertions(+), 1 deletion(-)

Fusion-Task-Id: FN-5805

Fusion-Task-Lineage: b1bcaf27-9bd7-4569-b685-225a97fa1200

packages/core/src/__tests__/global-settings.test.ts

@@ -219,6 +219,17 @@ describe("GlobalSettingsStore", () => {
       expect(settings.themeMode).toBe("dark"); // preserved default
     });
 
+    it("round-trips cliOnboardingCompletedAt without changing setupComplete", async () => {
+      await store.init();
+
+      const marker = "2026-05-31T00:00:00.000Z";
+      await store.updateSettings({ cliOnboardingCompletedAt: marker });
+
+      const settings = await store.getSettings();
+      expect(settings.cliOnboardingCompletedAt).toBe(marker);
+      expect(settings.setupComplete).toBeUndefined();
+    });
+
     it("round-trips testMode in global settings", async () => {
       await store.init();
 

packages/core/src/index.ts

@@ -769,7 +769,7 @@ export {
 
 export { CentralCore } from "./central-core.js";
 export type { CentralCoreEvents } from "./central-core.js";
-export { CentralDatabase, createCentralDatabase } from "./central-db.js";
+export { CentralDatabase, createCentralDatabase, getDefaultCentralDbPath } from "./central-db.js";
 export { NodeConnection } from "./node-connection.js";
 export { NodeDiscovery } from "./node-discovery.js";
 export { collectSystemMetrics } from "./system-metrics.js";

packages/core/src/settings-schema.ts

@@ -58,6 +58,7 @@ export const DEFAULT_GLOBAL_SETTINGS = {
   customProviders: [],
   defaultProjectId: undefined,
   setupComplete: undefined,
+  cliOnboardingCompletedAt: undefined,
   favoriteProviders: undefined,
   favoriteModels: undefined,
   openrouterModelSync: true,

packages/core/src/types.ts

@@ -2542,6 +2542,10 @@ export interface GlobalSettings {
    *  Set to true when the user completes the multi-project setup process.
    *  Default: false (undefined until setup is completed). */
   setupComplete?: boolean;
+  /** ISO timestamp for completion of the `fn onboard` CLI wizard.
+   *  Distinct from dashboard `setupComplete` first-run flow state.
+   *  Undefined means CLI onboarding has not completed yet. */
+  cliOnboardingCompletedAt?: string;
   /** List of favorite provider names. Favorite providers appear at the top of
    *  model selection dropdowns. Order is preserved - earlier entries appear higher. */
   favoriteProviders?: string[];