feat: add HTTP migration bridges and extensible API binding

httpx/context.go

@@ -3,6 +3,7 @@ package httpx
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"net/http"
 
 	apierrors "git.yuntuo.hk/k2safe/go-omni/errors"
@@ -101,12 +102,15 @@ func NewContext(request *http.Request, writer http.ResponseWriter, params map[st
 	if request == nil {
 		request = &http.Request{}
 	}
-	return &Context{
+	c := &Context{
 		request: request,
-		writer:  writer,
 		params:  params,
 		values:  make(map[string]any),
 	}
+	if writer != nil {
+		c.writer = trackWriter(writer, c)
+	}
+	return c
 }
 
 func (c *Context) Request() *http.Request { return c.request }
@@ -120,8 +124,8 @@ func (c *Context) Context() context.Context {
 	return c.request.Context()
 }
 
-// Raw returns the response writer supplied by the active network adapter.
-// Prefer the transport-neutral methods on Context for portable handlers.
+// Raw returns a streaming response writer that tracks commits and status.
+// Optional HTTP capabilities are preserved only when the underlying writer supports them.
 func (c *Context) Raw() http.ResponseWriter { return c.writer }
 
 // Clone gives a buffering middleware its own response state and values map.
@@ -146,7 +150,6 @@ func (c *Context) WriteResponse(status int, headers http.Header, body []byte) er
 	for key, values := range headers {
 		c.writer.Header()[key] = append([]string(nil), values...)
 	}
-	c.responded, c.status = true, status
 	c.writer.WriteHeader(status)
 	if len(body) > 0 {
 		if _, err := c.writer.Write(body); err != nil {
@@ -216,8 +219,6 @@ func (c *Context) JSON(status int, value any) error {
 	if err != nil {
 		return apierrors.Internal(err)
 	}
-	c.responded = true
-	c.status = status
 	c.writer.Header().Set("Content-Type", "application/json; charset=utf-8")
 	c.writer.WriteHeader(status)
 	if _, err := c.writer.Write(append(data, '\n')); err != nil {
@@ -243,8 +244,6 @@ func (c *Context) NoContent() error {
 	if c.writer == nil {
 		return apierrors.Internal(nil)
 	}
-	c.responded = true
-	c.status = http.StatusNoContent
 	c.writer.WriteHeader(http.StatusNoContent)
 	return nil
 }
@@ -271,12 +270,15 @@ func (c *Context) Status() int {
 func (c *Context) Responded() bool { return c.responded }
 
 // WriteError writes a stable public error response. Internal causes are not
-// serialized. Responses committed through Context methods are preserved;
-// direct Raw writes are outside this response-tracking contract.
+// serialized. Responses committed through Context methods or Raw are preserved.
 func (c *Context) WriteError(err error) {
 	if c.responded || err == nil {
 		return
 	}
+	var bodyErr *http.MaxBytesError
+	if errors.As(err, &bodyErr) {
+		err = bodyTooLarge()
+	}
 	apiErr := apierrors.From(err)
 	if writeErr := c.writeResult(response.Result{
 		Status:    apiErr.Status,