corpus: 416702 chunks, heap 557 MB, index 1625 MB
index definition: CREATE INDEX ix_chunks_embedding_hnsw ON public.chunks USING hnsw (embedding vector_cosine_ops) WITH (m='16', ef_construction='64')

--- the planner's own choice at production scale ---
  'How do I deploy gitea?'                 ef=100:HNSW(3333) ef=200:HNSW(5621) ef=400:HNSW(9806)
  'How do I deploy forgejo?'               ef=100:HNSW(3333) ef=200:HNSW(5621) ef=400:HNSW(9806)
  'How do I set up the gateway?'           ef=100:HNSW(3333) ef=200:HNSW(5621) ef=400:HNSW(9806)

--- latency + recall (production order) ---
  'How do I deploy gitea?'                 exact_seq=549.5ms  ef100: 12.4ms overlap=0.230 topΔ=7.9e-02  ef200: 11.9ms overlap=0.230 topΔ=7.9e-02  ef400: 12.5ms overlap=0.230 topΔ=7.9e-02
  'How do I deploy forgejo?'               exact_seq=545.8ms  ef100: 12.1ms overlap=0.470 topΔ=0.0e+00  ef200: 12.9ms overlap=0.470 topΔ=0.0e+00  ef400: 12.0ms overlap=1.000 topΔ=0.0e+00
  'How do I set up the gateway?'           exact_seq=553.1ms  ef100: 13.4ms overlap=0.640 topΔ=0.0e+00  ef200: 14.9ms overlap=0.640 topΔ=0.0e+00  ef400: 14.3ms overlap=0.640 topΔ=0.0e+00
