Initial commit: pwweb - PipeWire WebUI

C++ backend with SSE streaming (reuses qpwgraph PipeWire callbacks).
Svelte frontend with custom SVG canvas for port-level connections.

Features:
- Live PipeWire graph via SSE
- Drag output->input port to connect
- Double-click or select+Delete to disconnect
- Node positions saved to localStorage
- Pan (drag bg) and zoom (scroll)
- Port type coloring (audio=green, midi=red, video=blue)

CMakeLists.txt

@@ -0,0 +1,43 @@
+cmake_minimum_required(VERSION 3.16)
+project(pwweb VERSION 0.1.0 LANGUAGES C CXX)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+find_package(PkgConfig REQUIRED)
+pkg_check_modules(PW REQUIRED libpipewire-0.3)
+pkg_check_modules(SPA REQUIRED libspa-0.2)
+
+# ZLIB for cpp-httplib gzip compression
+find_package(ZLIB QUIET)
+
+add_executable(pwweb
+    src/main.cpp
+    src/graph_engine.cpp
+    src/web_server.cpp
+)
+
+target_include_directories(pwweb PRIVATE
+    src
+    src/third_party
+    ${PW_INCLUDE_DIRS}
+    ${SPA_INCLUDE_DIRS}
+)
+
+target_link_directories(pwweb PRIVATE
+    ${PW_LIBRARY_DIRS}
+    ${SPA_LIBRARY_DIRS}
+)
+
+target_link_libraries(pwweb PRIVATE
+    ${PW_LIBRARIES}
+    ${SPA_LIBRARIES}
+    pthread
+)
+
+if(ZLIB_FOUND)
+    target_link_libraries(pwweb PRIVATE ZLIB::ZLIB)
+    target_compile_definitions(pwweb PRIVATE CPPHTTPLIB_ZLIB_SUPPORT)
+endif()
+
+target_compile_options(pwweb PRIVATE ${PW_CFLAGS_OTHER} ${SPA_CFLAGS_OTHER})