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".

lib/apl/tests/pipeline.sx

@@ -397,8 +397,37 @@
   :dfn)
 
 (apl-test
-  "apl-run-file: source-then-call shape"
+  "apl-run-file: source-then-call returns primes count"
   (mksh
     (apl-run
       (str (file-read "lib/apl/tests/programs/primes.apl") " ⋄ primes 30")))
-  (list 0))
+  (list 10))
+
+(apl-test
+  "primes one-liner with ⍵-rebind: primes 30"
+  (mkrv
+    (apl-run "primes ← {(2=+⌿0=⍵∘.|⍵)/⍵←⍳⍵} ⋄ primes 30"))
+  (list 2 3 5 7 11 13 17 19 23 29))
+
+(apl-test
+  "primes one-liner: primes 50"
+  (mkrv
+    (apl-run "primes ← {(2=+⌿0=⍵∘.|⍵)/⍵←⍳⍵} ⋄ primes 50"))
+  (list 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47))
+
+(apl-test
+  "primes.apl loaded + called via apl-run-file"
+  (mkrv
+    (apl-run
+      (str (file-read "lib/apl/tests/programs/primes.apl") " ⋄ primes 20")))
+  (list 2 3 5 7 11 13 17 19))
+
+(apl-test
+  "primes.apl loaded — count of primes ≤ 100"
+  (first
+    (mksh
+      (apl-run
+        (str
+          (file-read "lib/apl/tests/programs/primes.apl")
+          " ⋄ primes 100"))))
+  25)