fix(mcpb): default bundle tools to empty array when omitted

[syf2211]

Summary

When publishing a .mcpb bundle whose manifest omits the tools key, getBundleDeployPayload produced a serverCard with only serverInfo. The Smithery registry rejects that payload with 400 {"error":"No values to set"}.

This change always includes tools in the deploy payload, defaulting to an empty array when the manifest does not declare tools.

Motivation

Fixes #770. Users reported publish failures for valid stdio bundles unless they manually edited manifest.json to add "tools": []. Issue comments traced the root cause to conditional spreading in getBundleDeployPayload.

Changes

• Default serverCard.tools to [] when manifest.tools is omitted
• Add unit tests for omitted and explicit tools manifest values

Tests

• pnpm test src/lib/__tests__/mcpb/get-bundle-deploy-payload.test.ts — 2 passed
• pnpm test — 399 passed
• pnpm run check — passed
• pnpm run typecheck — passed

Notes

• Explicit tools: [] in the manifest behaves the same as before
• prompts and resources remain optional; only tools needed defaulting for the reported registry validation error