apl: life.apl runs as-written (+5 e2e)

Five infrastructure fixes to make the Hui formulation
{1 ⍵ ∨.∧ 3 4 = +/+/¯1 0 1 ∘.⊖ ¯1 0 1 ⌽¨ ⊂⍵} work:

1. apl-each-dyadic: unbox enclosed-array scalar before pairing;
   preserve array results instead of disclosing
2. apl-outer: same dict-vs-number wrap detection
3. apl-reduce: dict-aware wrap in reducer; don't double-wrap
   the final result in apl-scalar when it's already a dict
4. broadcast-dyadic: leading-axis extension for shape-(k) vs
   shape-(k …) — `3 4 = M[5,5]` → shape (2 5 5)
5. :vec eval keeps non-scalar dicts intact (no flatten-to-first)

life.apl: drop leading ⊃ (Hui's ⊃ assumes inner-product produces
enclosed cell; our extension-style impl produces clean (5 5)).
Comment block in life.apl explains.

5 e2e tests: blinker oscillates period-2, 2×2 block stable,
empty grid stays empty, source file load via apl-run-file.

Full suite 578/578.

lib/apl/tests/programs/life.apl

@@ -1,16 +1,16 @@
 ⍝ Conway's Game of Life — toroidal one-liner
 ⍝
-⍝ The classic Roger Hui formulation:
-⍝   life ← {⊃1 ⍵ ∨.∧ 3 4 = +/ +/ ¯1 0 1 ∘.⊖ ¯1 0 1 ⌽¨ ⊂⍵}
+⍝ Roger Hui formulation (without leading ⊃, since our inner-product
+⍝ already produces a clean 2D board from a heterogeneous strand):
+⍝   life ← {1 ⍵ ∨.∧ 3 4 = +/ +/ ¯1 0 1 ∘.⊖ ¯1 0 1 ⌽¨ ⊂⍵}
 ⍝
 ⍝ Read right-to-left:
 ⍝   ⊂⍵                : enclose the board (so it's a single scalar item)
 ⍝   ¯1 0 1 ⌽¨ ⊂⍵      : produce 3 horizontally-shifted copies
 ⍝   ¯1 0 1 ∘.⊖ …      : outer-product with vertical shifts → 3×3 = 9 shifts
 ⍝   +/ +/ …           : sum the 9 boards element-wise → neighbor-count + self
-⍝   3 4 = …           : boolean — count is exactly 3 or exactly 4
+⍝   3 4 = …           : leading-axis-extended boolean — count is 3 (born) or 4 (survive)
 ⍝   1 ⍵ ∨.∧ …         : "alive next" iff (count=3) or (alive AND count=4)
-⍝   ⊃ …               : disclose back to a 2D board
 ⍝
 ⍝ Rules in plain language:
 ⍝   - dead cell + 3 live neighbors → born
@@ -19,4 +19,4 @@
 ⍝
 ⍝ Toroidal: edges wrap (rotate is cyclic).
 
-life ← {⊃1 ⍵ ∨.∧ 3 4 = +/ +/ ¯1 0 1 ∘.⊖ ¯1 0 1 ⌽¨ ⊂⍵}
+life ← {1 ⍵ ∨.∧ 3 4 = +/ +/ ¯1 0 1 ∘.⊖ ¯1 0 1 ⌽¨ ⊂⍵}