CI - TypeScript quickstart should use local package rather than npm version

[bfops]

As it says on the label. If we make local changes, even something as simple as bumping a version number, the quickstart will fail.

Example: https://github.com/clockworklabs/SpacetimeDB/actions/runs/18980261737/job/54210737052

[bfops]

From @cloutiertyler:

FWIW this is a non-trivial change because this is also used as a template. Fortunately #3539 improves the scripts that would do this