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>

src/CelerisLab/lbm/kernels/step/esopull_sync.cu

@@ -5,7 +5,7 @@
 // or encodes physical DDF back to EsoPull backing layout.
 // Each thread handles one cell from a compact index list.
 //
-// Included by kernel_v2.cu.  No standalone compilation.
+// Included by uniform.cu.  No standalone compilation.
 // ============================================================================
 
 #ifndef CELERIS_STEP_ESOPULL_SYNC_CU