chore: expose lib target + open-path profiling examples

Examples can't import from a bin-only crate, so add a thin lib.rs that
re-exports the existing modules. Used by the new examples that helped
diagnose the freeze fixed in the previous commit.

- examples/time_open: times parse / purge / cache / first-wires phases
- examples/inspect_insert: lists Insert blocks with sub-entity counts
- examples/find_raster: dumps RasterImage path + dimensions

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/lib.rs

@@ -0,0 +1,10 @@
+pub mod app;
+pub mod command;
+pub mod entities;
+pub mod io;
+pub mod linetypes;
+pub mod modules;
+pub mod patterns;
+pub mod scene;
+pub mod snap;
+pub mod ui;