[Core] Add realtime AR-Diffusion tick sessions for LingBot World 2.0 (#5491)

Signed-off-by: zhangbin.327 <zhangbin.327@bytedance.com>
Signed-off-by: Jack47 <scsvip@gmail.com>
Co-authored-by: zhangbin.327 <zhangbin.327@bytedance.com>
Co-authored-by: Hongsheng Liu <liuhongsheng4@huawei.com>

tests/diffusion/ar_diffusion/test_paged_attention.py

@@ -332,7 +332,7 @@ def test_block_table_padded_to_fixed_width():
 
 def test_prepare_is_idempotent_and_layers_share_metadata():
     device = torch.device("cpu")
-    _, st = make_state(num_layers=2)
+    kv, st = make_state(num_layers=2)
     contexts = st.get_kv_caches(POS, seq_len=BLOCK, commit_current=False)
     fctx = contexts[0].forward_ctx
     fctx.prepare(device=device, action_len=0, query_len=BLOCK)
@@ -349,6 +349,10 @@ def test_prepare_is_idempotent_and_layers_share_metadata():
     assert i0.block_table is i1.block_table
     assert i0.seq_lens is i1.seq_lens
     assert i0.video_slots is i1.video_slots
+    assert i0.key_pool is kv._k_pools[0]
+    assert i0.value_pool is kv._v_pools[0]
+    assert i1.key_pool is kv._k_pools[1]
+    assert i1.value_pool is kv._v_pools[1]
 
 
 def test_layer_inputs_before_prepare_raises():