1. SkyServe will use the same strategy as managed jobs if no cloud storage is available. Description copied from controller_utils.translate_local_file_mounts_to_two_hop:

    This strategy will upload the local files to the controller first, using a
    normal rsync as part of sky.launch() for the controller. Then, when the
    controller launches the task, it will also use local file_mounts from the
    destination path of the first hop.

    Local machine/API server        Controller              Job cluster
    ------------------------  -----------------------  --------------------
    |      local path  ----|--|-> controller path --|--|-> job dst path   |
    ------------------------  -----------------------  --------------------

2. Add a config toggle that will force this file mount method even if cloud storage is enabled.

docs TODO

Tested (run the relevant ones):

• Code formatting: install pre-commit (auto-check on commit) or bash format.sh
• Any manual or new tests for this PR (please specify below)
• All smoke tests: /smoke-test (CI) or pytest tests/test_smoke.py (local)
• Relevant individual tests: /smoke-test -k test_name (CI) or pytest tests/test_smoke.py::test_name (local)
• Backward compatibility: /quicktest-core (CI) or pytest tests/smoke_tests/test_backward_compat.py (local)