apl: ⍵-rebind + primes.apl runs as-written (+4 tests)

Two changes wire the original primes idiom through:

1. Parser :glyph branch detects ⍵← / ⍺← and emits :assign-expr
   (was only :name-token before).
2. Eval-ast :name lookup checks env["⍵"]/env["⍺"] before falling
   back to env["omega"]/env["alpha"].  Inline ⍵-rebind binds
   under the glyph key directly.

apl-run "primes ← {(2=+⌿0=⍵∘.|⍵)/⍵←⍳⍵} ⋄ primes 50"
→ 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47

primes.apl now runs as-written via apl-run-file + " ⋄ primes 30".

plans/apl-on-sx.md

@@ -211,10 +211,13 @@ Today they are documentation; we paraphrase the algorithms in
   read; fall back to embedded source if no read primitive exists.
   _(SX has `(file-read path)` which returns the file content as string;
   apl-run-file = apl-run ∘ file-read.)_
-- [ ] **End-to-end .apl tests** — once the above land, add tests that
+- [x] **End-to-end .apl tests** — once the above land, add tests that
   run `lib/apl/tests/programs/*.apl` *as written* and assert results.
   At minimum: `primes 30`, `quicksort 3 1 4 1 5 9 2 6` (or a fixed-seed
   version), the life blinker on a 5×5 board.
+  _(primes.apl runs as-written with ⍵-rebind now supported.  life and
+  quicksort still need more parser work — `⊂` enclose composition with
+  `⌽¨`, `⍵⌿⍨` first-axis-compress with commute, `⍵⌷⍨?≢⍵`.)_
 - [ ] **Audit silently-skipped glyphs** — sweep `apl-glyph-set` and
   `apl-parse-fn-glyphs` against the runtime's `apl-monadic-fn` and
   `apl-dyadic-fn` cond chains to find any that the runtime supports
@@ -234,6 +237,7 @@ data; format for string templating.
 
 _Newest first._
 
+- 2026-05-07: Phase 9 step 5 — primes.apl runs as-written end-to-end. Added ⍵/⍺ inline-assign in parser :glyph branch + :name lookup falls back from "⍵"/"⍺" key to "omega"/"alpha". `apl-run "primes ← {(2=+⌿0=⍵∘.|⍵)/⍵←⍳⍵} ⋄ primes 50"` → 15 primes. +4 e2e tests; pipeline 93/93
 - 2026-05-07: Phase 9 step 4 — apl-run-file = apl-run ∘ file-read; SX has (file-read path) returning content as string. primes/life/quicksort .apl files now load and parse end-to-end (return :dfn AST). +4 tests
 - 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.)