test: cover push with circuit-only project

[vahapogut]

Fixes #2797

Summary

• Add a regression test for tsci push when a package has only a *.circuit.tsx board file.
• Assert the push uploads the circuit file and publishes without requiring index.circuit.tsx or mainEntrypoint.

Verification

• bun test tests/cli/push/push1-no-entrypoint.test.ts -t "should push when the project only has a circuit file"
• bun x biome check tests/cli/push/push1-no-entrypoint.test.ts
• bun x tsc --noEmit
• git diff --check

Note

• bun install initially tried to build sharp and failed on this Windows toolchain; rerunning with bun install --ignore-scripts installed the dependency tree for tests/typecheck.