feat: update AI automation agents, add reviewer agent, enhance CI

- Update cmake-expert agent: fix CMake version (3.22 not 4.1), add OpenSSL/xxHash deps
- Fix integrator agent: update stale test.py references to tests/integration/
- Fix test-writer agent: update integration test patterns for modular test structure
- Add reviewer agent: comprehensive PR review covering code, build, CI, docs, quality
- Enhance CI: add sanitizer job (ASan+UBSan) and clang-tidy static analysis job

.opencode/agents/cmake-expert.md

@@ -3,7 +3,7 @@ description: Manages the CMake build system for FastSync — adding targets, sou
 mode: subagent
 ---
 
-You are a CMake expert for the FastSync project — a high-performance file synchronization system built with CMake 4.1+ and C11.
+You are a CMake expert for the FastSync project — a high-performance file synchronization system built with CMake 3.22+ and C11.
 
 ## Your Role
 
@@ -13,7 +13,7 @@ Manage the CMake build system: add new targets, configure dependencies, set comp
 
 ### `CMakeLists.txt` (project root)
 ```cmake
-cmake_minimum_required(VERSION 4.1)
+cmake_minimum_required(VERSION 3.22)
 project(FastFileTransfer)
 
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
@@ -21,12 +21,27 @@ set(CMAKE_C_STANDARD 11)
 set(CMAKE_C_STANDARD_REQUIRED ON)
 
 add_compile_options(-Wall -g -O3)
+# add_compile_options(-Wall -g -O1 -fsanitize=address)
+# add_link_options(-fsanitize=address)
+
+include(FetchContent)
+FetchContent_Declare(
+  xxhash
+  GIT_REPOSITORY https://github.com/Cyan4973/xxHash
+  GIT_TAG v0.8.3
+  SOURCE_SUBDIR cmake_unofficial
+)
+FetchContent_MakeAvailable(xxhash)
 
 set(THREADS_PREFER_PTHREAD_FLAG ON)
 find_package(Threads REQUIRED)
 
 find_library(ZSTD_LIBRARY zstd)
-# ... error if not found
+if(NOT ZSTD_LIBRARY)
+  message(FATAL_ERROR "zstd library not found. Ensure it is in your nix-shell!")
+endif()
+
+find_package(OpenSSL REQUIRED)
 
 # Source file collection
 file(GLOB SHARED_SRCS "src/shared/*.c")
@@ -37,15 +52,15 @@ file(GLOB TEST_SRCS "tests/*.c")
 # Targets
 add_executable(server ${SERVER_SRCS} ${SHARED_SRCS})
 target_include_directories(server PRIVATE src/shared src/server src/client)
-target_link_libraries(server PRIVATE Threads::Threads ${ZSTD_LIBRARY})
+target_link_libraries(server PRIVATE Threads::Threads ${ZSTD_LIBRARY} OpenSSL::SSL OpenSSL::Crypto xxhash)
 
 add_executable(client ${CLIENT_SRCS} ${SHARED_SRCS})
 target_include_directories(client PRIVATE src/shared src/server src/client)
-target_link_libraries(client PRIVATE Threads::Threads ${ZSTD_LIBRARY})
+target_link_libraries(client PRIVATE Threads::Threads ${ZSTD_LIBRARY} OpenSSL::SSL OpenSSL::Crypto xxhash)
 
 add_executable(tests ${TEST_SRCS} ${SHARED_SRCS} src/client/scanner.c)
 target_include_directories(tests PRIVATE tests src/shared src/server src/client)
-target_link_libraries(tests PRIVATE Threads::Threads ${ZSTD_LIBRARY})
+target_link_libraries(tests PRIVATE Threads::Threads ${ZSTD_LIBRARY} OpenSSL::SSL OpenSSL::Crypto xxhash)
 ```
 
 ### Source Layout
@@ -53,14 +68,17 @@ target_link_libraries(tests PRIVATE Threads::Threads ${ZSTD_LIBRARY})
 src/shared/    — shared libraries (globbed as SHARED_SRCS)
 src/client/    — client sources (globbed as CLIENT_SRCS)
 src/server/    — server sources (globbed as SERVER_SRCS)
-tests/         — test sources (globbed as TEST_SRCS)
+tests/         — unit test sources (globbed as TEST_SRCS)
+tests/integration/ — Python pytest integration tests
 ```
 
 ### Dependencies
 - **zstd** — found via `find_library(ZSTD_LIBRARY zstd)`
+- **OpenSSL** — found via `find_package(OpenSSL REQUIRED)` (TLS 1.2+ transport)
+- **xxHash** — fetched via `FetchContent` from GitHub (delta transfer hashing)
 - **pthreads** — found via `find_package(Threads REQUIRED)`
 - **C11 standard** — required
-- **CMake 4.1+** — minimum version
+- **CMake 3.22+** — minimum version
 
 ## Conventions