[Bugfix][EC Connector] Size transfers by measured encoder output widths (#57904)

Signed-off-by: Tianyu Guo <guoty@inferact.ai>

docs/features/ec_cpu_connector.md

@@ -96,7 +96,7 @@ EC transfer is configured via `--ec-transfer-config` (CLI) or the `ec_transfer_c
 | --- | --- | --- | --- |
 | `ec_enable_nixl` | `bool` | No (default `false`) | Enables NIXL P2P transfer in addition to local CPU offload. Omitted or `false` imports no NIXL/ZMQ. Extra config is not type coerced, so a string value is parsed: `"true"`, `"1"`, `"yes"` enable it, anything else does not. |
 | `consumer_ack_timeout_s` | `float` | No (default `2.0`) | How long a consumer waits for an `XferAck` before giving up on a read. The producer answers `XferReq`s from its own scheduler step, so its reply latency scales with the encoder's `--max-num-batched-tokens`: a loaded encoder whose steps run longer than this makes consumers abandon reads the producer is about to grant. Raise it for large encoder batches. |
-| `ec_cpu_bytes` | `int` | Yes | Total size, in bytes, of the shared CPU mmap region. `ECCPUConnector` raises `ValueError` if unset. Block count = `ec_cpu_bytes // block_size_bytes`, where `block_size_bytes = hidden_dim * dtype.element_size()` (`hidden_dim` accounts for Qwen3-VL deepstack: `out_hidden_size * (1 + num_deepstack_layers)`). |
+| `ec_cpu_bytes` | `int` | Yes | Total size, in bytes, of the shared CPU mmap region. `ECCPUConnector` raises `ValueError` if unset. Block count = `ec_cpu_bytes // block_size_bytes`, where each block holds one LLM input-embedding vector. Entries allocate enough blocks for their modality-specific output shape, including visual DeepStack features. |
 
 ### Environment Variables