E14: mating systems — monogamy vs promiscuity (mate-pool breadth)

A new analytic experiment on an orthogonal evolution-of-sex axis: not the
recombination RATE (E9) but the population's mating STRUCTURE. Agents on a
ring recombine with a second parent drawn from a window of breadth b
(b->0 monogamous/isolation-by-distance, b=1 promiscuous/panmictic), under
local selection, swept against NK ruggedness K.

Finding: the optimal mate-pool breadth SHRINKS as skills get more
entangled. Wide/promiscuous merging wins the champion on additive
landscapes (K<=3, b=0.6), but on rugged ones (K>=6) it prematurely
converges to a worse champion and an intermediate breadth (b~0.35) wins;
pure monogamy over-fragments. Throughout, promiscuity monotonically lifts
the population MEAN but destroys diversity and parallel exploration. The
design rule extends E9: merge widely for additive skills, keep
island-structured sub-populations for entangled ones — a merging-native
axis the panmixia-assuming literature lacks.

- src/knowledge/mating_system.py + experiment.py dispatch (kind: mating_system)
- configs/layer1/E14.yaml (breadth x K sweep, 20 reps, bitwise-reproducible)
- figures/plot_E14.py; results/E14/ (figure, README, manifest, resolved config)
- tests/test_mating_system.py (+5, 147 green); make layer1 wired
- folded into both papers (full + accessible) as the third §5 result

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

results/E14/resolved_config.yaml

@@ -0,0 +1,33 @@
+experiment: E14
+seed: 20260709
+n_replicates: 20
+source_config:
+  experiment: E14
+  kind: mating_system
+  seed: 20260709
+  n_replicates: 20
+  mating:
+    L: 12
+    N: 48
+    breadth: 1.0
+    K: 0
+    recomb_rate: 0.5
+    mu: 0.003
+  generations: 60
+  sweep:
+  - param: mating.K
+    values:
+    - 0
+    - 3
+    - 6
+    - 10
+  - param: mating.breadth
+    values:
+    - 0.03
+    - 0.08
+    - 0.17
+    - 0.35
+    - 0.6
+    - 1.0
+  output:
+    dir: results/E14