fix: support uv MCPB bundle publishing

[ebeirne]

Summary

• recognize MCPB 0.4 server.type: "uv" bundles as Smithery''s Python deployment runtime
• add a focused regression test that builds a real MCPB archive and verifies the generated deploy payload

Why

MCPB manifest v0.4 adds a uv server type for Python servers whose dependencies are installed by the host. Smithery currently throws Could not determine bundle runtime from manifest before uploading these valid bundles.

Smithery''s stdio deployment API models runtimes as node | binary | python | bun, so this maps the MCPB uv subtype to the Python runtime family without altering the bundle manifest.

This is a draft pending maintainer confirmation that Smithery''s Python deployment image supports executing the bundle''s uv command.

Verification

• pnpm exec vitest run src/lib/__tests__/mcpb/get-bundle-deploy-payload.test.ts
• pnpm run typecheck
• pnpm run build
• Biome check on both changed files
• git diff --check
• Full suite on Windows: 395 passed; 3 unrelated existing platform failures (two tests expect Unix npx output, one requires symlink privileges)

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Note

Low Risk
Single-branch runtime detection change plus a unit test; no auth or API contract changes beyond allowing previously rejected valid bundles.

Overview
Fixes MCPB 0.4 bundles that declare server.type: "uv" failing publish with Could not determine bundle runtime from manifest by treating uv the same as python in detectBundleRuntime, so deploy payloads use Smithery’s existing python stdio runtime without changing the manifest on disk.

Adds a regression test that zips a minimal manifest.json with type: "uv" and asserts getBundleDeployPayload returns runtime: "python" plus expected server card metadata.

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