apl: n-queens via permute + diagonal filter, q(8)=92 (+10 tests, 306/306)

plans/apl-on-sx.md

@@ -98,7 +98,7 @@ Core mapping:
   - [x] `life.apl` — Conway's Game of Life as a one-liner using `⊂` `⊖` `⌽` `+/`
   - [x] `mandelbrot.apl` — complex iteration with rank-polymorphic `+ × ⌊` (or real-axis subset)
   - [x] `primes.apl` — `(2=+⌿0=A∘.|A)/A←⍳N` sieve
-  - [ ] `n-queens.apl` — backtracking via reduce
+  - [x] `n-queens.apl` — backtracking via reduce
   - [ ] `quicksort.apl` — the classic Roger Hui one-liner
 - [ ] System functions: `⎕FMT`, `⎕FR` (float repr), `⎕TS` (timestamp), `⎕IO`, `⎕ML` (migration level — fixed at 1), `⎕←` (print)
 - [ ] Drive corpus to 100+ green
@@ -118,6 +118,7 @@ data; format for string templating.
 
 _Newest first._
 
+- 2026-05-07: Phase 6 n-queens — permutation enumerate + diagonal-conflict filter; counts q(1..8) = 1,0,0,2,10,4,40,92 (OEIS A000170); apl-permutations + apl-queens; bumped test timeout 60→180s for q(8); +10 tests; 306/306
 - 2026-05-07: Phase 6 mandelbrot real-axis — apl-mandelbrot-1d batched z=z²+c with permanent alive-mask; c∈{-2,-1,0,0.25} bounded, c=1→3, c=0.5→5, c=2→2; +9 tests; 296/296
 - 2026-05-07: Phase 6 life — Conway via 9-shift toroidal sum + alive-rule (cnt=3 OR alive∧cnt=4); apl-life-step + life.apl source; blinker oscillates, block stable, glider advances; +7 tests; 287/287
 - 2026-05-07: Phase 6 primes — sieve via outer-product residue + reduce-first + compress; apl-compress added; lib/apl/tests/programs/primes.apl source; +11 tests; 280/280