Launcher updates

Once a day, project run checks whether a newer DevCapsule release exists and tells you interactively; --no-update-check skips the check for one launch, and a cached critical notice still lets you decide. Installing the newer release is the install block again, with the new version's download address; it replaces the executable and nothing else.

An upgraded launcher keeps every project's lock and every checkout's recorded choices. It grants no new host access. If a project changed its own configuration in the meantime, the next launch asks you to resolve, as Project versus personal describes. A checkout last launched by a much older client may be asked once for a vendor-download consent that older clients did not record.