Surfaced running the DB libraries (migratus) on the jolt db library:
- java.sql.SQLException .getNextException / .getStackTrace / .printStackTrace on
jolt throwables (conditions + ex-info) return nil/empty, so a library walking
the exception chain doesn't crash.
- java.net.URL ctor + .getProtocol (file/http), alongside the existing url shim.
- A generic java.lang.ClassLoader: getSystemClassLoader / a thread's
contextClassLoader resolve a named resource against the source roots (the same
model as clojure.java.io/resource) — file: URL or nil. Thread/currentThread.
These are generic host capabilities, not DB-specific.
The jolt-lang/db next.jdbc surface now runs migratus far enough to connect, build
the migrations table, and discover migrations; migratus's remaining dependency is
java.nio.file (FileSystems/Path/PathMatcher glob), a JVM filesystem API kept out
of core.