feat: LLM accuracy testing framework with 17-test catalog

Framework runs a category/subcategory test catalog against multiple
LLMs through an OpenAI-compatible endpoint. Deterministic evaluators
score each response. Reports render as table, markdown, or JSON.

internal/tests/catalog.go

@@ -0,0 +1,24 @@
+package tests
+
+import "github.com/lukaszraczylo/llm-testbench/internal/testkit"
+
+// All builds a Registry containing the full 17-test catalog: 3
+// programming/golang, 2 programming/python, 1 programming/typescript, 1
+// programming/c, 2 operations/macos, 2 operations/linux, 1
+// operations/kubernetes, 1 research/web, 1 research/whitepapers, 1
+// research/codebase, and 2 agents (tool-routing, planning).
+func All() *testkit.Registry {
+	r := testkit.NewRegistry()
+	registerGolangTests(r)
+	registerPythonTests(r)
+	registerTypeScriptTests(r)
+	registerCTests(r)
+	registerMacOSTests(r)
+	registerLinuxTests(r)
+	registerKubernetesTests(r)
+	registerWebTests(r)
+	registerWhitepapersTests(r)
+	registerCodebaseTests(r)
+	registerAgentsTests(r)
+	return r
+}