corpus: 62 DocLayNet val pages

=== Table 1: API x Metric (mean over pages) ===
metric                   spectre       pymupdf
----------------------------------------------
pair_f1                    0.545         0.607
ari                        0.490         0.541
v_measure                  0.762         0.683
token_micro_f1             0.860         0.775
boundary_f1                0.623         0.387

  (n per cell ~ 47 pages)

=== Table 2: synthetic-partition pair_f1 (sensitivity) ===
candidate                       mean pair_f1    median
------------------------------------------------------
all tokens in 1 block (under)          0.303     0.259
each token own block (over)            0.000     0.000
spectre observed (ref)                 0.545     0.567
pymupdf observed (ref)                 0.607     0.584

=== Table 3: spectre alignment sensitivity ===
alignment                            pair_f1           ari     n
----------------------------------------------------------------
token first-occurrence                 0.545         0.490    47
bbox overlap                           0.584         0.514    42
Δ (bbox − token)                      +0.039
