native test framework

TODO.md

@@ -897,6 +897,16 @@
   - `tag!` reads or folds a tagged union discriminant, while `tagname!` turns a comptime-known enum
     value into its immutable field-name string
 
+41. native test framework (implemented; v1)
+  - `name test { ... }` declares an implicit `void ! testing.Error` test omitted from executable builds
+  - anonymous `test import` edges discover dependency tests transitively; ordinary imports remain
+    separate namespaces and never discover tests
+  - direct `@std/testing` `expect` and expected-first `expect_equal` calls inject their source locations
+  - `brolang test` reuses `build.bro`, runs tests sequentially, continues after assertion failures,
+    prints a summary, and returns failure when a test fails or traps
+  - filtering, skipping, fixtures, snapshots, parallelism, isolation, allocators, and more assertion
+    families remain deferred
+
 ## A word on unchecked casts
 
 For casts that bypass safety checks, Honey provides builtin functions: