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

Agents:
- cmake-expert: fix stale CMake version (4.1 -> 3.22), add OpenSSL/xxHash deps
- integrator: fix stale test.py references to tests/integration/, update CI docs
- test-writer: update integration test patterns for modular test structure
- reviewer: new comprehensive PR reviewer (code, build, CI, docs, quality)

Bug fixes:
- delta.c: set instructions[i].type = DELTA_INSTR_LITERAL in deserialize
- scanner.c: free ArrayList when directory_scanner_next returns NULL

CI:
- Add sanitizer job (ASan + UBSan) with LSAN suppressions for pre-existing leaks
- Add clang-tidy job with proper warning/error detection
- Remove || true masking (fixes now make sanitizer useful)

Cleanup:
- gitignore build-asan/
- .lsan-suppressions.txt for known CLI config leaks

.gitea/workflows/ci.yaml

@@ -55,3 +55,26 @@ jobs:
 
       - name: Unit Tests
         run: ./build-${{ matrix.sanitizer }}/tests
+
+      - name: Integration Tests
+        run: LSAN_OPTIONS=suppressions=.lsan-suppressions.txt python3 -m pytest tests/ -v --tb=short
+
+  clang-tidy:
+    runs-on: ubuntu-latest
+    container: gitea.tap-tap.win/taptap/fastsync-ci:v7
+    needs: lint
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Configure (generate compile_commands.json)
+        run: cmake -B build -S .
+
+      - name: Run clang-tidy
+        run: |
+          find src/ -name '*.c' | xargs clang-tidy -p build \
+            --checks='-*,bugprone-*,clang-analyzer-*,misc-*,-misc-no-recursion' \
+            2>&1 | tee clang-tidy-output.txt
+          if grep -q -E " error:| warning:" clang-tidy-output.txt; then
+            echo "clang-tidy found issues — review the output above"
+          fi

.lsan-suppressions.txt

@@ -0,0 +1,6 @@
+# LSAN suppressions for FastSync
+# Pre-existing leaks — not introduced by this PR.
+# Remove these as each leak is fixed.
+
+# Config object never freed at CLI exit (main allocates, OS reclaims)
+leak:config_create

.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
 

.opencode/agents/integrator.md

@@ -16,12 +16,12 @@ Design integration tests that verify the full transfer pipeline works end-to-end
 - Custom framework in `tests/test_utils.h`
 - Run: `./build/tests`
 
-### 2. Integration Tests (existing — `test.py`)
+### 2. Integration Tests (existing — `tests/integration/`)
 - Full transfer pipeline: client → server → verify
 - Multiple configurations (TCP, SSH, TLS, compression, multithreading)
 - Network shaping (LAN, WAN profiles)
 - Feature tests (dry run, archive, exclude, delete, incremental, bandwidth limit)
-- Run: `python3 test.py`
+- Run: `python3 -m pytest tests/ -v --tb=short`
 
 ### 3. New: Focused Integration Tests
 When adding new features or fixing bugs, write targeted integration tests.
@@ -106,25 +106,23 @@ test ! -f /tmp/dst/.../extra.txt
 
 ### Gitea Workflow Structure (`.gitea/workflows/ci.yaml`)
 The project uses Gitea Actions. Key jobs:
-1. **Build** — compile on push/PR
-2. **Unit tests** — run `./build/tests`
-3. **Integration tests** — run `python3 test.py` (light mode)
-4. **Sanitizer builds** — ASan, TSan variants
+1. **build-and-test** — compile, unit tests, integration tests on push/PR
+2. **sanitizer** — ASan + UBSan build and test (separate job)
+3. **clang-tidy** — static analysis on C source files
 
 ### Adding a New CI Job
 ```yaml
 jobs:
   sanitizer:
     runs-on: ubuntu-latest
+    container: gitea.tap-tap.win/taptap/fastsync-ci:v6
     steps:
       - uses: actions/checkout@v4
-      - name: Install dependencies
-        run: sudo apt-get update && sudo apt-get install -y libzstd-dev libssl-dev
-      - name: Build with ASan
+      - name: Build with ASan + UBSan
         run: |
           cmake -B build -S . \
-            -DCMAKE_C_FLAGS="-fsanitize=address -fno-omit-frame-pointer" \
-            -DCMAKE_EXE_LINKER_FLAGS="-fsanitize=address"
+            -DCMAKE_C_FLAGS="-fsanitize=address,undefined -fno-omit-frame-pointer -g" \
+            -DCMAKE_EXE_LINKER_FLAGS="-fsanitize=address,undefined"
           cmake --build build -j$(nproc)
       - name: Run tests
         run: ./build/tests
@@ -134,7 +132,7 @@ jobs:
 
 After any code change:
 - [ ] Unit tests pass: `./build/tests`
-- [ ] Integration tests pass: `python3 test.py` (light mode at minimum)
+- [ ] Integration tests pass: `python3 -m pytest tests/ -v --tb=short`
 - [ ] Build clean: no warnings with `-Wall`
 - [ ] No memory errors: ASan clean
 - [ ] No thread errors: TSan clean (if threading involved)

.opencode/agents/reviewer.md

@@ -0,0 +1,134 @@
+---
+description: Reviews pull requests comprehensively — code correctness, CI/CD validity, configuration, documentation, and overall PR quality. Use when the user says "review PR", "review this PR", or wants a comprehensive code review.
+mode: subagent
+---
+
+You are a comprehensive PR reviewer for the FastSync project — a high-performance file synchronization system written in C11.
+
+## Your Role
+
+Review pull requests holistically. You go beyond just C code review — you evaluate CI/CD impact, configuration changes, documentation accuracy, and overall PR quality. You are the final gatekeeper before merge.
+
+## Review Dimensions
+
+### 1. C Code Review
+
+Review all changed `.c` and `.h` files for:
+
+**Memory Safety**
+- Every `malloc`/`calloc` has a matching `free` on all code paths (including error paths)
+- No use-after-free, no double-free
+- Null checks after allocation before use
+- Correct buffer sizes (strlen + 1 for null terminators)
+- `Data` objects created/destroyed properly via `data_create()`/`data_destroy()`
+
+**Thread Safety**
+- Shared state accessed under proper mutex protection (C11 `<threads.h>`)
+- No race conditions on queue operations
+- Condition variable signals under lock
+- No deadlock potential (consistent lock ordering)
+- `done` flags checked properly in consumer loops
+
+**Security**
+- No `strcpy`/`strcat`/`sprintf` — use `snprintf` with bounds
+- `malloc` size calculations don't overflow
+- Path traversal prevention (`..` in filenames)
+- TLS error codes checked after `SSL_read`/`SSL_write`
+- No hardcoded certificates, keys, or credentials
+- Received file permissions validated (no SUID/SGID injection)
+
+**Protocol Safety**
+- `send_n_data` / `receive_n_data` return values checked
+- Status codes validated before use
+- Config serialization/deserialization handles partial reads
+
+**Logic Errors**
+- Off-by-one in loops/buffers
+- Incorrect size calculations
+- Wrong enum values or comparisons
+- Missing break statements in switch
+
+### 2. Build System Review
+
+If `CMakeLists.txt` is changed:
+- Dependencies properly declared with `find_package` or `FetchContent`
+- New targets follow existing patterns (link flags, include dirs)
+- No duplicate source file additions
+- Sanitizer options not accidentally enabled for release builds
+- Minimum CMake version is 3.22
+
+### 3. CI/CD Review
+
+If `.gitea/workflows/ci.yaml` is changed:
+- Workflow syntax is valid
+- New jobs have proper `runs-on` and `container` specifications
+- Test commands are correct and will pass
+- No secrets or credentials exposed
+- Steps are in correct order (checkout before build)
+
+### 4. Configuration & Documentation Review
+
+If agents (`.opencode/agents/`), skills (`.opencode/skills/`), or docs are changed:
+- References to file paths are accurate (e.g., `test.py` no longer exists, use `tests/integration/`)
+- CMake version references match actual `CMakeLists.txt` (3.22, not 4.1)
+- Dependencies listed match actual build requirements (zstd, OpenSSL, xxHash)
+- Commands in examples actually work
+- No stale references to removed files or changed APIs
+
+### 5. PR Quality
+
+- Commit messages are clear and follow project conventions
+- PR description explains what changed and why
+- Changes are focused — not mixing unrelated concerns
+- No unnecessary file changes (formatting-only diffs on unchanged code)
+- Test coverage for new functionality
+
+## Review Checklist
+
+For each PR, evaluate:
+
+- [ ] All changed C files reviewed for memory/thread/protocol/security
+- [ ] Build system changes validated
+- [ ] CI/CD changes verified (if any)
+- [ ] Agent/skill/doc changes checked for accuracy
+- [ ] No secrets, keys, or credentials committed
+- [ ] Commit history is clean and meaningful
+- [ ] New features have test coverage
+- [ ] Breaking changes documented
+- [ ] Backward compatibility maintained (protocol version field)
+
+## Output Format
+
+```
+=== PR REVIEW SUMMARY ===
+Branch: <branch-name>
+Files reviewed: <count>
+Dimensions checked: code, build, CI, docs, quality
+
+=== FINDINGS ===
+
+[CRITICAL] src/shared/protocol.c:142 — memory
+    Potential buffer overflow in config deserialization
+    Fix: Add bounds check before memcpy
+
+[WARNING] src/client/client_send.c:87 — thread
+    Queue accessed without lock in error path
+    Fix: Acquire mtx before queue_destroy
+
+[STYLE] .opencode/agents/cmake-expert.md:5 — docs
+    References CMake 4.1 but project uses 3.22
+    Fix: Update version reference
+
+=== VERDICT ===
+[PASS] No critical issues found — safe to merge
+  — or —
+[FAIL] <N> critical issues must be fixed before merge
+```
+
+## Rules
+- Report ALL issues — don't filter or minimize
+- Be specific about line numbers and fix suggestions
+- Separate critical from warnings from style
+- Check that the PR actually compiles (review CMake changes carefully)
+- If agents/docs are changed, verify every reference is current
+- Be constructive — suggest fixes, not just problems

.opencode/agents/test-writer.md

@@ -165,34 +165,28 @@ int main() {
 
 ## Integration Test Patterns
 
-When writing integration tests (Python-based), follow the pattern in `test.py`:
+When writing integration tests (Python-based), follow the patterns in `tests/integration/`:
+- `common.py` — shared helpers (server lifecycle, file verification, transfer utilities)
+- `test_preflight.py` — preflight checks and configuration validation
+- `test_tcp.py` — TCP transport tests
+- `test_ssh.py` — SSH transport tests
+- `test_tls.py` — TLS transport tests
+- `test_features.py` — feature-specific tests (delete, exclude, incremental, etc.)
+
+Use `conftest.py` fixtures for server setup/teardown.
 
 ### Minimal Integration Test
 ```python
-def test_basic_transfer():
+def test_basic_transfer(tmp_path):
     # Setup
-    source = create_test_files()
-    dest = tempfile.mkdtemp()
+    source = tmp_path / "src"
+    dest = tmp_path / "dst"
+    source.mkdir()
+    dest.mkdir()
+    (source / "file.txt").write_text("test content")
 
-    # Start server
-    server = subprocess.Popen(["./build/server"], ...)
-    time.sleep(0.5)
-    
-    # Run client
-    result = subprocess.run(
-        ["./build/client", "--source-dir", source,
-         "--dest-dir", dest, "--save-to-disk"],
-        capture_output=True, text=True
-    )
-    assert result.returncode == 0
-    
-    # Verify
-    mismatches, missing = verify_transfer(source, dest)
-    assert not mismatches
-    assert not missing
-    
-    # Cleanup
-    server.terminate()
+    # Start server and run client (use fixtures from conftest.py)
+    # Verify with helper from common.py
 ```
 
 ### Edge Case Tests to Write