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

.lsan-suppressions.txt

@@ -0,0 +1,6 @@
+# LSAN suppressions for FastSync
+# Add suppression entries here for known pre-existing leaks that cannot be
+# fixed immediately. Remove entries as leaks are fixed.
+#
+# Example format:
+# leak:function_name