gemma4: fix namespace dflash27b -> dflash::common after rebase

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: howard0su

dflash/src/gemma4/gemma4_backend.cpp

@@ -936,7 +936,7 @@ bool Gemma4Backend::handle_compress(const std::string & line,
 
 void Gemma4Backend::free_drafter() {
     if (drafter_loaded_) {
-        dflash27b::free_drafter(drafter_ctx_);
+        ::dflash::common::free_drafter(drafter_ctx_);
         drafter_loaded_ = false;
     }
 }

dflash/src/gemma4/gemma4_dflash_target.cpp

@@ -7,7 +7,7 @@
 #include <cmath>
 #include <cstdio>
 
-namespace dflash27b {
+namespace dflash::common {
 
 Gemma4DFlashTarget::Gemma4DFlashTarget(
         Gemma4Weights & w,
@@ -148,4 +148,4 @@ const std::vector<int> & Gemma4DFlashTarget::capture_layer_ids() const {
     return capture_ids_;
 }
 
-}  // namespace dflash27b
+}  // namespace dflash::common

dflash/src/gemma4/gemma4_dflash_target.h

@@ -14,7 +14,7 @@
 
 #include <vector>
 
-namespace dflash27b {
+namespace dflash::common {
 
 class Gemma4DFlashTarget : public DFlashTarget {
 public:
@@ -60,4 +60,4 @@ class Gemma4DFlashTarget : public DFlashTarget {
     Gemma4Snapshot verify_snap_;
 };
 
-}  // namespace dflash27b
+}  // namespace dflash::common