refactor: move process files to api/process/

Move process-related files from bindings/ to api/process/:
- BunProcess, ProcessBindingBuffer, ProcessBindingConstants
- ProcessBindingFs, ProcessBindingHTTPParser, ProcessBindingNatives
- ProcessBindingTTYWrap, ProcessBindingUV, ProcessIdentifier
- bun-spawn

Part of source code reorganization to make code location "guessable".

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

cmake/Sources.json

@@ -75,6 +75,7 @@
       "src/buntime/api/test/*.cpp",
       "src/buntime/api/server/*.cpp",
       "src/buntime/api/plugin/*.cpp",
+      "src/buntime/api/process/*.cpp",
       "src/bake/*.cpp",
       "src/deps/*.cpp",
       "src/vm/*.cpp",

cmake/targets/BuildBun.cmake

@@ -522,12 +522,12 @@ set(BUN_OBJECT_LUT_SOURCES
   ${CWD}/src/buntime/bindings/BunObject.cpp
   ${CWD}/src/buntime/bindings/ZigGlobalObject.lut.txt
   ${CWD}/src/buntime/bindings/JSBuffer.cpp
-  ${CWD}/src/buntime/bindings/BunProcess.cpp
-  ${CWD}/src/buntime/bindings/ProcessBindingBuffer.cpp
-  ${CWD}/src/buntime/bindings/ProcessBindingConstants.cpp
-  ${CWD}/src/buntime/bindings/ProcessBindingFs.cpp
-  ${CWD}/src/buntime/bindings/ProcessBindingNatives.cpp
-  ${CWD}/src/buntime/bindings/ProcessBindingHTTPParser.cpp
+  ${CWD}/src/buntime/api/process/BunProcess.cpp
+  ${CWD}/src/buntime/api/process/ProcessBindingBuffer.cpp
+  ${CWD}/src/buntime/api/process/ProcessBindingConstants.cpp
+  ${CWD}/src/buntime/api/process/ProcessBindingFs.cpp
+  ${CWD}/src/buntime/api/process/ProcessBindingNatives.cpp
+  ${CWD}/src/buntime/api/process/ProcessBindingHTTPParser.cpp
   ${CWD}/src/buntime/modules/NodeModuleModule.cpp
   ${CODEGEN_PATH}/ZigGeneratedClasses.lut.txt
 )
@@ -887,6 +887,7 @@ target_include_directories(${bun} PRIVATE
   ${CWD}/src/buntime/api/test
   ${CWD}/src/buntime/api/server
   ${CWD}/src/buntime/api/plugin
+  ${CWD}/src/buntime/api/process
   ${CWD}/src/buntime/modules
   ${CWD}/src/js/builtins
   ${CWD}/src/napi