HS: coll-feats error on unconsumed tokens (+1 test)

When parse-feat returns nil but the token stream is not at EOF,
coll-feats now throws a parse error ('Unexpected token X') instead
of silently returning the partial result. Fixes 'extra chars cause
error when evaling': eval-hs("1!") now correctly throws because '!'
is left over after parsing the number expression.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/hyperscript/parser.sx

@@ -3133,7 +3133,19 @@
             acc
             (let
               ((feat (parse-feat)))
-              (if (nil? feat) acc (coll-feats (append acc (list feat))))))))
+              (if
+                (nil? feat)
+                (if
+                  (at-end?)
+                  acc
+                  (error
+                    (str
+                      "Parse error: Unexpected token '"
+                      (tp-val)
+                      "' (line "
+                      (get (nth tokens p) "line")
+                      ")")))
+                (coll-feats (append acc (list feat))))))))
       (let
         ((features (coll-feats (list))))
         (if

shared/static/wasm/sx/hs-parser.sx

@@ -3133,7 +3133,19 @@
             acc
             (let
               ((feat (parse-feat)))
-              (if (nil? feat) acc (coll-feats (append acc (list feat))))))))
+              (if
+                (nil? feat)
+                (if
+                  (at-end?)
+                  acc
+                  (error
+                    (str
+                      "Parse error: Unexpected token '"
+                      (tp-val)
+                      "' (line "
+                      (get (nth tokens p) "line")
+                      ")")))
+                (coll-feats (append acc (list feat))))))))
       (let
         ((features (coll-feats (list))))
         (if