fix(cpp): out-of-bounds read in delete() when a location is passed

[pbbadenhorst]

Summary

The delete JSI host function in cpp/DBHostObject.cpp checks count == 1 for the optional location argument, but then reads args[1] instead of args[0]. Calling db.delete(location) therefore reads past the end of the JSI argument list — undefined behaviour, can crash native code.

Also fixes a stale error string in the same block that referred to [op-sqlite][open] instead of [op-sqlite][delete].

Changes

• cpp/DBHostObject.cpp: use args[0] for the optional location argument; correct the error message tag.
• example/src/tests/dbsetup.ts: add two regression tests — one that calls db.delete(location) with a valid string, and one that asserts a non-string argument is rejected by the type guard.

[oscar-opacity]

err, no, there is some error there, but the delete function was meant to replicate the same behavior as open where you could pass a base path + name of the db as separate arguments. It's a broken artifact of the many migrations over the years. I will take a look later.