kernels: name compilation entries by storage route (uniform.cu, blocked.cu)

kernel_v2.cu -> uniform.cu (whole-domain NX/NY, Simulation) and
blocks.cu -> blocked.cu (one block window, every blocked level), with
InitTubeFlow_v2 -> InitTubeFlow. All live callers, include comments,
CONFIG.md, lifecycle doc and current-tree tests move together; no alias.
refinement.cu keeps its name until the dense-route decision.
Historical-revision tooling that names the old files (LES source pins,
timing/J campaign runners, TG run_case, supported_settings citations at
888c8038, development notes) is unchanged on purpose.
No arithmetic change; the PTX symbol InitTubeFlow_v2 is renamed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/integration/test_runtime_contracts_gpu.py

@@ -13,7 +13,7 @@ from ._cases import make_sim
 def test_source_provenance():
     root = Path(__file__).resolve().parents[2] / "src/CelerisLab"
     assert Path(CelerisLab.__file__).resolve().parent == root
-    assert Path(compiler_v2.kernel_path("kernel_v2.cu")).resolve() == root / "lbm/kernels/kernel_v2.cu"
+    assert Path(compiler_v2.kernel_path("uniform.cu")).resolve() == root / "lbm/kernels/uniform.cu"
 
 
 def test_two_contexts_interleaved_and_non_lifo_close():