apl: ? roll/random + apl-rng-seed! (+4 tests)

apl-rng-state global mutable LCG.
apl-rng-seed! for deterministic tests.
apl-rng-next! advances state.
apl-roll: monadic ?N returns scalar in 1..N (apl-io-relative).

apl-monadic-fn dispatches "?" → apl-roll.

apl-run "?10" → 8 (with seed 42)
apl-run "?100" → in 1..100

plans/apl-on-sx.md

@@ -202,7 +202,7 @@ Today they are documentation; we paraphrase the algorithms in
   :dyad/:monad capture env update when their RHS is :assign-expr, threading
   the new binding into the LHS evaluation.  Caveat: ⍵ rebinding is
   glyph-token, not :name-token — covered for regular names like `a ← ⍳N`.)_
-- [ ] **`?` (random / roll)** — monadic `?N` returns a random integer
+- [x] **`?` (random / roll)** — monadic `?N` returns a random integer
   in 1..N.  Used by quicksort.apl for pivot selection.  Add `apl-roll`
   (deterministic seed for tests) + glyph wiring.
 - [ ] **`apl-run-file path → array`** — read the file from disk, strip
@@ -232,6 +232,7 @@ data; format for string templating.
 
 _Newest first._
 
+- 2026-05-07: Phase 9 step 3 — `?N` random / roll. Top-level mutable apl-rng-state with LCG; apl-rng-seed! for deterministic tests; apl-roll wraps as scalar in 1..N. apl-monadic-fn maps "?" → apl-roll. +4 tests (deterministic with seed 42, range checks)
 - 2026-05-07: Phase 9 step 2 — inline assignment `(2=+⌿0=a∘.|a)/a←⍳30` runs end-to-end. Parser :name clause detects `name ← rhs`, consumes rest as RHS, emits :assign-expr segment. Eval-ast :dyad/:monad capture env update when their right operand is :assign-expr. +5 tests (one-liner primes via inline assign, x+x←7=14, dfn-internal inline assign, etc.)
 - 2026-05-07: Phase 9 step 1 — compress-as-fn / and ⌿; collect-segments-loop emits (:fn-glyph "/") when slash stands alone; apl-dyadic-fn dispatches / → apl-compress, ⌿ → apl-compress-first (new helper); classic primes idiom now runs end-to-end: `P ← ⍳ 30 ⋄ (2 = +⌿ 0 = P ∘.| P) / P` → primes; queens(8) test removed again (q(8) climbed to 215s on this server load); +5 tests; 501/501
 - 2026-05-07: Phase 9 added — make .apl source files run as-written (compress as dyadic /, inline assignment, ? random, apl-run-file, glyph audit, source-as-tests)