Add the Go binding over the C ABI hub (#228)

Adds a Go binding (`bindings/go`) over the C ABI hub — the second language stecker after C#.

## What's here
- **`bindings/go`** — a cgo binding exposing all 514 indicators as idiomatic Go types with `New<Indicator>` constructors and `Update`/`Batch`/`Reset`/`Close` methods. The wrappers in `indicators_gen.go` are generated from `bindings/c/include/wickra.h` (same archetype taxonomy as the C# generator: scalar/batch, multi-output, bars, profile, profile-values, array-input). Opaque handles are freed by `Close()` with a `runtime.SetFinalizer` backstop; pointer arguments are caller-owned, panics never cross the boundary.
- **`examples/go`** — the full example suite mirroring C/C#: streaming, backtest, multi_timeframe, parallel_assets (goroutine fan-out), three strategies, and `fetch_btcusdt`/`live_binance`.
- **CI** — a `go` job builds the C ABI library, stages it, and runs `gofmt`/`go vet`/`go test` plus the offline examples on Linux, macOS and Windows.
- **Docs** — Go added to the README languages table, project layout, building/testing, CONTRIBUTING binding table + regenerate note, ARCHITECTURE, examples index, issue/PR templates, the About-description template, and the other binding READMEs.

## Linking / distribution
The binding links the prebuilt C ABI library via cgo (`libwickra.so`/`.dylib`/`wickra.dll` staged under `bindings/go/lib`, gitignored). The native libraries are already shipped per target triple by the existing `c-abi-build` release job; distribution is via the subdirectory module tag `bindings/go/vX.Y.Z` (gated), so `release.yml` needs no new publish job.

No Rust crate or `Cargo.toml` change — the Go module is standalone and additive.

Not for merge yet (gated, per request).

examples/go/live_binance/main.go

@@ -0,0 +1,54 @@
+// Stream live BTCUSDT 1-minute klines from Binance and feed each close through EMA(20).
+// Requires network access (build-only in CI). Runs for up to 60 seconds.
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"strconv"
+	"time"
+
+	"github.com/coder/websocket"
+	wickra "github.com/wickra-lib/wickra/bindings/go"
+)
+
+func main() {
+	const url = "wss://stream.binance.com:9443/ws/btcusdt@kline_1m"
+	fmt.Printf("Connecting to %s (up to 60s)...\n", url)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
+	defer cancel()
+
+	conn, _, err := websocket.Dial(ctx, url, nil)
+	if err != nil {
+		log.Fatalf("dial: %v", err)
+	}
+	defer conn.CloseNow()
+
+	ema, _ := wickra.NewEma(20)
+	defer ema.Close()
+
+	for {
+		_, data, err := conn.Read(ctx)
+		if err != nil {
+			fmt.Println("Done (time limit reached).")
+			return
+		}
+
+		var msg struct {
+			K struct {
+				Close string `json:"c"`
+			} `json:"k"`
+		}
+		if err := json.Unmarshal(data, &msg); err != nil || msg.K.Close == "" {
+			continue
+		}
+		closePx, err := strconv.ParseFloat(msg.K.Close, 64)
+		if err != nil {
+			continue
+		}
+		fmt.Printf("close=%.2f  EMA(20)=%.2f\n", closePx, ema.Update(closePx))
+	}
+}