feat(tunnel): switch to yamux stream proxying and connection pooling

- Introduce pooled tunnel sessions (TunnelID/DataConnect) on client/server
- Proxy HTTP/HTTPS via raw HTTP over yamux streams; pipe TCP streams directly
- Move UI/stats into internal/shared; refactor CLI tunnel helpers; drop msgpack/hpack legacy

internal/shared/pool/adaptive_buffer_pool.go

@@ -1,73 +0,0 @@
-package pool
-
-import (
-	"sync"
-)
-
-// AdaptiveBufferPool manages reusable buffers of different sizes
-// This eliminates the massive memory allocation overhead seen in profiling
-type AdaptiveBufferPool struct {
-	// Large buffers for streaming threshold (1MB)
-	largePool *sync.Pool
-
-	// Medium buffers for temporary reads (32KB)
-	mediumPool *sync.Pool
-}
-
-const (
-	// LargeBufferSize is 1MB for streaming threshold
-	LargeBufferSize = 1 * 1024 * 1024
-
-	// MediumBufferSize is 32KB for temporary reads
-	MediumBufferSize = 32 * 1024
-)
-
-// NewAdaptiveBufferPool creates a new adaptive buffer pool
-func NewAdaptiveBufferPool() *AdaptiveBufferPool {
-	return &AdaptiveBufferPool{
-		largePool: &sync.Pool{
-			New: func() interface{} {
-				buf := make([]byte, LargeBufferSize)
-				return &buf
-			},
-		},
-		mediumPool: &sync.Pool{
-			New: func() interface{} {
-				buf := make([]byte, MediumBufferSize)
-				return &buf
-			},
-		},
-	}
-}
-
-// GetLarge returns a large buffer (1MB) from the pool
-// The returned buffer should be returned via PutLarge when done
-func (p *AdaptiveBufferPool) GetLarge() *[]byte {
-	return p.largePool.Get().(*[]byte)
-}
-
-// PutLarge returns a large buffer to the pool for reuse
-func (p *AdaptiveBufferPool) PutLarge(buf *[]byte) {
-	if buf == nil {
-		return
-	}
-	// Reset to full capacity to allow reuse
-	*buf = (*buf)[:cap(*buf)]
-	p.largePool.Put(buf)
-}
-
-// GetMedium returns a medium buffer (32KB) from the pool
-// The returned buffer should be returned via PutMedium when done
-func (p *AdaptiveBufferPool) GetMedium() *[]byte {
-	return p.mediumPool.Get().(*[]byte)
-}
-
-// PutMedium returns a medium buffer to the pool for reuse
-func (p *AdaptiveBufferPool) PutMedium(buf *[]byte) {
-	if buf == nil {
-		return
-	}
-	// Reset to full capacity to allow reuse
-	*buf = (*buf)[:cap(*buf)]
-	p.mediumPool.Put(buf)
-}

internal/shared/pool/header_pool.go

@@ -1,86 +0,0 @@
-package pool
-
-import (
-	"net/http"
-	"sync"
-)
-
-// HeaderPool manages a pool of http.Header objects for reuse.
-type HeaderPool struct {
-	pool sync.Pool
-}
-
-// NewHeaderPool creates a new header pool
-func NewHeaderPool() *HeaderPool {
-	return &HeaderPool{
-		pool: sync.Pool{
-			New: func() interface{} {
-				return make(http.Header, 12)
-			},
-		},
-	}
-}
-
-// Get retrieves a header from the pool.
-func (p *HeaderPool) Get() http.Header {
-	h := p.pool.Get().(http.Header)
-	for k := range h {
-		delete(h, k)
-	}
-	return h
-}
-
-// Put returns a header to the pool.
-func (p *HeaderPool) Put(h http.Header) {
-	if h == nil {
-		return
-	}
-	p.pool.Put(h)
-}
-
-// Clone creates a copy of src into dst, reusing dst's underlying storage
-// This is more efficient than creating a new header from scratch
-func (p *HeaderPool) Clone(dst, src http.Header) {
-	// Clear dst first
-	for k := range dst {
-		delete(dst, k)
-	}
-
-	// Copy all headers from src to dst
-	for k, vv := range src {
-		// Allocate new slice with exact capacity to avoid over-allocation
-		dst[k] = make([]string, len(vv))
-		copy(dst[k], vv)
-	}
-}
-
-// CloneWithExtra clones src into dst and adds/overwrites extra headers
-// This is optimized for the common pattern of cloning + adding Host header
-func (p *HeaderPool) CloneWithExtra(dst, src http.Header, extraKey, extraValue string) {
-	// Clear dst first
-	for k := range dst {
-		delete(dst, k)
-	}
-
-	// Copy all headers from src to dst
-	for k, vv := range src {
-		dst[k] = make([]string, len(vv))
-		copy(dst[k], vv)
-	}
-
-	// Set extra header (overwrite if exists)
-	dst.Set(extraKey, extraValue)
-}
-
-// globalHeaderPool is a package-level pool for convenience
-var globalHeaderPool = NewHeaderPool()
-
-// GetHeader retrieves a header from the global pool
-func GetHeader() http.Header {
-	return globalHeaderPool.Get()
-}
-
-// PutHeader returns a header to the global pool
-func PutHeader(h http.Header) {
-	globalHeaderPool.Put(h)
-}