feat(data): native live Binance kline feed in 9 languages (+ 3d/1M intervals) (#313)

* feat(data): C-ABI Binance feed + Go binding (F4 wip)

C ABI exposes the existing async BinanceKlineStream (tokio + TLS, auto-reconnect,
mock-server-tested in wickra-data) through a blocking poll: wickra_binance_connect
/ _next(out, timeout_ms) -> {1 event, 0 timeout, -1 closed} / _close / _free over
an opaque BinanceStream that owns a current-thread runtime. WickraKlineEvent
carries OHLCV + open_time + is_closed + a 16-byte symbol buffer. `live-binance`
is now a default feature of wickra-c (the published DLL ships the feed; the wasm
build drops it via --no-default-features).

Go: NewBinanceFeed(symbols, interval, baseURL) + Next(timeout) + Close, with a
deterministic error-path smoke (the connect->event pipeline is covered by the
Rust mock-WS-server tests).

* feat(data): Binance feed C# + Java bindings (F4 wip)

C#: BinanceFeed(symbols, interval, baseUrl?) + Next(timeout) -> KlineEvent? +
Dispose; bespoke WickraKlineEvent native struct (fixed symbol buffer + byte
is_closed) since the scalar struct parser can't model it. `char` maps to `byte`
for the const char* params.

Java: BinanceFeed + KlineEvent record + BinanceInterval enum over Panama FFM;
the event is read at hand-computed offsets (symbol@0, doubles@16..48,
open_time@56, is_closed@64; 72-byte struct). Both with deterministic error-path
smokes (pipeline covered by the Rust mock-WS-server tests).

* feat(data): Binance feed R binding (F4 wip)

R: BinanceFeed(symbols, interval, base_url) + binance_next(feed, timeout_ms) ->
named list | NULL + binance_close, via bespoke .Call glue (wk_binance_*). The
glue + its registration entries are gated out of the Emscripten/wasm build
(#ifndef __EMSCRIPTEN__) since r-universe/webR has no raw sockets. NAMESPACE
exports added by hand (roxygen2 not installed locally). Deterministic error-path
smoke; pipeline covered by the Rust mock-WS-server tests.

* feat(data): native Binance feed for Node + Python; CHANGELOG (F4 complete)

Node (napi) BinanceFeed: new(symbols, interval, baseUrl?) + next(timeoutMs) ->
KlineEvent | null + close. Python (pyo3) BinanceFeed: same, with next releasing
the GIL (py.detach) while it waits. Both drive the mock-server-tested async
BinanceKlineStream on a single-thread tokio runtime (blocking poll); wickra-data
gains the live-binance feature + tokio in each binding.

Completes F4: the live Binance kline feed is now native in all 9 languages
(WASM excluded), with no third-party WebSocket client in any of them.

bindings/c/include/wickra.h

@@ -102,6 +102,8 @@ typedef struct BetaNeutralSpread BetaNeutralSpread;
 
 typedef struct BetterVolume BetterVolume;
 
+typedef struct BinanceStream BinanceStream;
+
 typedef struct BipowerVariation BipowerVariation;
 
 typedef struct BodySizePct BodySizePct;
@@ -1690,6 +1692,17 @@ typedef struct WickraCandle {
     int64_t timestamp;
 } WickraCandle;
 
+typedef struct WickraKlineEvent {
+    uint8_t symbol[16];
+    double open;
+    double high;
+    double low;
+    double close;
+    double volume;
+    int64_t open_time;
+    bool is_closed;
+} WickraKlineEvent;
+
 #ifdef __cplusplus
 extern "C" {
 #endif // __cplusplus
@@ -13748,6 +13761,18 @@ uintptr_t wickra_candle_reader_read(struct CandleReader *handle,
 
 void wickra_candle_reader_free(struct CandleReader *handle);
 
+struct BinanceStream *wickra_binance_connect(const char *symbols,
+                                             uint8_t interval,
+                                             const char *base_url);
+
+int32_t wickra_binance_next(struct BinanceStream *handle,
+                            struct WickraKlineEvent *out,
+                            int64_t timeout_ms);
+
+void wickra_binance_close(struct BinanceStream *handle);
+
+void wickra_binance_free(struct BinanceStream *handle);
+
 #ifdef __cplusplus
 }  // extern "C"
 #endif  // __cplusplus