PR review fixes:
- docs (en/zh) mci.md: add missing variable definitions (n, ids, data, q)
  to the example snippets so they are self-contained and compilable.
- src/algorithm/mci.cpp: replace std::getenv("VSAG_MCI_BUILD_STATS") and
  std::cerr instrumentation with logger::debug so the standard logger
  level controls verbosity; relax the limited_size != 0 check; extract
  the duplicated heap-to-dataset construction into
  MCI::build_dataset_from_heap helper shared by KNN and range search.
- src/algorithm/mci.{h,cpp,_parameter.cpp}: drop the redundant
  hgraph_serialized_size field from Serialize/Deserialize; hybrid loading
  now relies solely on hgraph_index_path. MCIParameter::ToJson now
  serializes hgraph_index_path so JSON round-trips are complete.
- tools/eval/monitor/recall_monitor.cpp: align the result-tuple cast with
  SearchEvalCase's actual std::tuple<const int64_t*, ...> type, removing
  an undefined-behavior reinterpret_cast.

Tests:
- tests/test_mci.cpp: new functional test suite covering build/search
  across metrics and base quantization types, filter search, reorder
  (rabitq one-bit), concurrent KNN, the three serialization paths
  (binary set / reader set / file), the hybrid overlay path with a
  decoupled hgraph index loaded via hgraph_index_path, and a
  RandomAllocator robustness case.

Signed-off-by: zhuangye.yxw <2510035537@qq.com>
Assisted-by: CodeFuse:claude-sonnet-4.5

clang-format-15 noted layout drift in four files introduced by the MCI
feature; this commit applies the formatter output verbatim so the
"check_format" CI job stops failing.

- examples/cpp/322_feature_mci_hybrid_filter.cpp
- src/algorithm/mci.cpp
- src/algorithm/mci_test.cpp  (also: append trailing newline)
- tools/eval/export_knng.cpp

Signed-off-by: zhuangye.yxw <2510035537@qq.com>
Assisted-by: CodeFuse:claude-sonnet-4.5

…ecks

The CHECK_ARGUMENT macro expands to `if (not(expr)) { ... }`; when
`expr` itself is a compound `A and B` (or `not X or Y`) clang-tidy's
readability-simplify-boolean-expr treats the resulting AST as
DeMorgan-reducible and fails the CI lint job at -warnings-as-errors.

Split the two affected MCI checks onto two lines and trail the first
clause with `// NOLINT`, mirroring the existing pattern in
src/algorithm/hgraph/hgraph_param_mapping.cpp:488.

Signed-off-by: zhuangye.yxw <2510035537@qq.com>
Assisted-by: CodeFuse:claude-sonnet-4.5

Resolve the 7 clang-tidy-15 errors reported by the CI lint job
(`readability-*` and `bugprone-narrowing-conversions`):

- L54  readability-static-definition-in-anonymous-namespace:
       drop redundant `static` from MCI_PARAMS_TEMPLATE (already in
       anonymous namespace).
- L217 readability-suspicious-call-argument: silence with NOLINT on
       the symmetric `set_core_edge(rhs, lhs)` companion call; this is
       intentional for undirected edge insertion.
- L453 readability-identifier-naming: rename struct
       `MCISearchCandidate` -> `mci_search_candidate` to match the
       project's `StructCase: lower_case` rule. Updated all 4 use sites.
- L627 bugprone-narrowing-conversions: cast `extra_info_size_`
       (`uint64_t`) to `int64_t` when calling `make_temporary_sq8_flatten`,
       mirroring `hgraph_build.cpp:147`.
- L708, L1939 readability-simplify-boolean-expr: split each
       compound `CHECK_ARGUMENT` predicate across two lines and trail
       the first clause with `// NOLINT`, same pattern as
       `hgraph_param_mapping.cpp:488` and `mci_parameter.cpp` (this PR).
- L1891 readability-qualified-auto: declare `vectors` as
       `const auto*` (the function already returns `const float*`).

Verified locally with clang-tidy-15 (0 errors/warnings on mci.cpp +
mci_parameter.cpp) and `build/tests/functests "[mci]"` passes 21173
assertions across 7 test cases.

Signed-off-by: zhuangye.yxw <2510035537@qq.com>
Assisted-by: CodeFuse:claude-sonnet-4.5

Add lazy clique maintenance for incremental MCI Add, persist embedded HGraph state, and add evaluation utilities for full-build versus incremental comparisons.

Document the incremental flow and add a runnable C++ example.

Signed-off-by: zhuangye.yxw <2510035537@qq.com>
Assisted-by: Codex:GPT-5

- Fix data race in add_dataset: acquire global_mutex_ when mutating
  p_node_to_cid_ to prevent concurrent read/write with search threads.
- Add empty-heap early return in build_dataset_from_heap to avoid
  unsigned underflow when range search yields no results.
- Add debug log when hybrid routing is silently disabled due to
  hgraph/mci size mismatch after incremental Add.
- Document best-effort coverage semantics of try_select_clique under
  parallel builds.

Signed-off-by: zhuangye.yxw <2510035537@qq.com>
Assisted-by: ClaudeCode:claude-opus-4-6

Signed-off-by: zhuangye.yxw <2510035537@qq.com>
Assisted-by: ClaudeCode:claude-opus-4-6