feat(maps-test): migrate to test-lib (manifest.lib + run_tests) (Test-Opt Phase 3.1)

Per ADR-0037 Tests-as-Libs Convention.

- manifest.module -> manifest.lib with role: 'test'
- init(ctx) -> M.run_tests(ctx) entry-point export
- No assertion-body change

Repo renamed on Gitea: sporel-module-lib-core.maps-test -> sporel-lib-core.maps-test
Local moved: sporel-modules/lib-core.maps-test/ -> sporel-libs/lib-core/maps-test/
History preserved.

init.lua

@@ -1,11 +1,13 @@
 -- =====================================================================
--- lib-core.maps-test — Reference test-module (P.3.1)
+-- lib-core.maps-test — Reference test-lib (P.3.1)
 -- Validates lib-core.maps API contracts via engine.test.* assertions.
 -- See: meta/docs/superpowers/specs/2026-05-10-test-module-pattern-design.md
 -- =====================================================================
 local maps = require("lib-core.maps")
 
-function init(ctx)
+local M = {}
+
+function M.run_tests(ctx)
     -- Setup
     local demo_map = maps.load("maps/demo.map.json")
     maps.set_current(demo_map)
@@ -35,3 +37,5 @@ function init(ctx)
 
     engine.exit(engine.test.failures())
 end
+
+return M