treewide: migrate to multi-crate layout

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I11a2103f3530f07409177404577b90136a6a6964

crates/pakker-core/src/lib.rs

@@ -0,0 +1,21 @@
+#![expect(
+  clippy::multiple_crate_versions,
+  reason = "transitive dependency version conflicts from upstream crates"
+)]
+#![expect(
+  clippy::cargo_common_metadata,
+  reason = "license and repository not yet configured"
+)]
+
+pub mod error;
+pub mod export;
+pub mod fetch;
+pub mod git;
+pub mod http;
+pub mod ipc;
+pub mod model;
+pub mod platform;
+pub mod rate_limiter;
+pub mod resolver;
+pub mod ui_utils;
+pub mod utils;