feat: add run() and binary entry points for all servers and init

Every server now has lib.rs (testable) + main.rs (deployable binary).
Binary is 3 lines: extern crate userspace_rt + call run().
Hardware servers use feature flags for adapter selection.
9 RISC-V binaries ready for the disk image.

crates/servers/storage-server/src/lib.rs

@@ -10,3 +10,17 @@ pub mod server;
 #[cfg(test)]
 #[path = "tests/mod.rs"]
 mod tests;
+
+pub fn run() -> ! {
+    #[cfg(feature = "qemu-virt")]
+    {
+        let device = adapters::mock_block::MockBlockDevice::new(64);
+        let filesystem = fs::fat16::Fat16::mount(device);
+        if let Some(mut fs) = filesystem {
+            let mut srv = server::StorageServer::new(fs);
+            server_framework::serve(&mut srv, 0);
+        }
+    }
+
+    loop { userspace::syscall::yield_now(); }
+}