[gouyt13]

Closes #214

This migrates the seven remaining files off the 0.7 call forms: test_ivf.py, test_hnsw.py, test_symqg.py, test_input_boundaries.py, test_ivf_initializers.py, test_portable_indexes.py and test_import.py. #226 and #227 migrated the other eleven. Every test file except the four exempt ones (test_compat_08.py, test_txtai_compat.py, test_train_api.py, test_symqg_api.py) now passes with -W error::DeprecationWarning.

Changes

• Constructors take no max_elements. HNSW passes nbits and num_clusters explicitly. Where a test needs room for more points, it calls resize, as in partial_hnsw.
• build becomes set_centroids plus add:
  • Calls that relied on build's single thread pass num_threads=1.
  • Explicit thread counts and fast_quantization carry over.
  • test_ivf.py and test_hnsw.py each gain a small _built helper for the dozen or so cases that set centroids and add data.
• Expectations that follow 0.8 behavior. What each test checks is unchanged.
  • Messages. set_centroids and HNSW add report their own messages for a wrong centroid shape or an out-of-range cluster ID.
  • Training on first add. An untrained IvfIndex trains on its first add, so "add before training raises" now passes cluster_ids, as the HNSW test already did.
  • search_batch. The SymphonyQG validation test uses search, since search_batch is a deprecated alias.
  • Access guard. In test_path_callback_runs_before_access_guard, the SymphonyQG case calls add, its only write, inside the path callback. A free guard gives the "incremental addition" error; a held guard would give Index is busy.

Moved to test_compat_08.py or deleted

Tests of behavior with no 0.8 form. Each moved test is wrapped in quietly; #213 deletes that file.

Test	From	Action
test_build_row_count_diagnostics	test_input_boundaries.py	moved
test_failed_rebuild_preserves_index	test_symqg.py	moved
test_successful_rebuild_replaces_index	test_symqg.py	moved
default init of SymqgIndex.build (one assertion)	test_symqg.py	moved
test_invalid_quantization_bits_raises	test_symqg.py	deleted: test_symqg_mixed_or_invalid_old_forms covers it
test_rejected_rebuild_preserves_index	test_hnsw.py	moved
test_zero_capacity_raises	test_hnsw.py	moved
test_rebuild_matches_incremental_encoding_with_empty_clusters	test_ivf.py	moved: rebuilding a loaded index through build has no 0.8 form; C++ IvfConstructionTest covers the same encoding

IVF HNSW routing threads

IvfIndex.set_centroids has no num_threads and builds the HNSW routing graph with every CPU. The 0.7 build passed its thread count through. Two tests are affected:

• test_hnsw_centroid_routing_roundtrip (128 centroids) checks every centroid's self-recall in aggregate, at least 97%, instead of four exact matches. A parallel hnswlib build may leave a centroid unreachable (Make graph-index tests independent of graph connectivity #216).
• test_hnsw_parallel_build_routes_and_reloads: threads now applies to add and search only.

A follow-up PR adds num_threads to IvfIndex.set_centroids. The C++ method already takes it. That PR also restores both tests.

Checks

On Linux x86-64, Xeon Gold 6418H, GCC 14.3, Release, native optimization off; the package was built from main.

• The seven files under -W error::DeprecationWarning: 428 passed.
• Every file except the four exempt ones under the same flag: 1,003 passed, 2 skipped.
• Full Python suite: 1,146 passed, 2 skipped.
• check-python.sh passes.
• The seven files plus test_compat_08.py in a loop: 208 runs, 0 failures. These runs include the graph builds that now use every CPU.