HS runtime: empty/swap/compound events, host-set! fix — 403→423 (51%)

- Fix host-set → host-set! in emit-inc/emit-dec (increment/decrement properties)
- Implement empty/clear command: parser dispatch, compiler, polymorphic runtime
- Implement swap command: parser dispatch, compiler (let+do temp swap pattern)
- Add parse-compound-event-name: joins dot/colon tokens (example.event, htmx:load)
- Add hs-compile to source parser (was only in WASM deploy copy)
- Add clear/swap to tokenizer keywords and cmd-kw? list
- Generator: fix run() with extra args, String.raw support

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lib/hyperscript/parser.sx

@@ -942,12 +942,40 @@
                     (if (= (tp-type) "comma") (adv!) nil)
                     (dd-collect (append acc (list key val))))))))
           (cons (quote dict) (dd-collect (list)))))
+      (define
+        parse-compound-event-name
+        (fn
+          ()
+          (let
+            ((result (get (adv!) "value")))
+            (define
+              collect!
+              (fn
+                ()
+                (when
+                  (not (at-end?))
+                  (cond
+                    ((= (tp-type) "class")
+                      (let
+                        ((part (tp-val)))
+                        (adv!)
+                        (set! result (str result "." part))
+                        (collect!)))
+                    ((= (tp-type) "local")
+                      (let
+                        ((part (tp-val)))
+                        (adv!)
+                        (set! result (str result ":" part))
+                        (collect!)))
+                    (true nil)))))
+            (collect!)
+            result)))
       (define
         parse-send-cmd
         (fn
           ()
           (let
-            ((name (get (adv!) "value")))
+            ((name (parse-compound-event-name)))
             (let
               ((dtl (if (= (tp-type) "paren-open") (parse-detail-dict) nil)))
               (let
@@ -1422,6 +1450,21 @@
             (let
               ((end-pos (skip-to-close 0)))
               (substring src start-pos end-pos)))))
+      (define
+        parse-empty-cmd
+        (fn
+          ()
+          (let
+            ((target (cond ((at-end?) (list (quote sym) "me")) ((and (= (tp-type) "keyword") (or (= (tp-val) "then") (= (tp-val) "end"))) (list (quote sym) "me")) (true (parse-expr)))))
+            (list (quote empty-target) target))))
+      (define
+        parse-swap-cmd
+        (fn
+          ()
+          (let
+            ((lhs (parse-expr)))
+            (match-kw "with")
+            (let ((rhs (parse-expr))) (list (quote swap!) lhs rhs)))))
       (define
         parse-cmd
         (fn
@@ -1503,6 +1546,12 @@
                 (do (adv!) (parse-halt-cmd)))
               ((and (= typ "keyword") (= val "focus"))
                 (do (adv!) (parse-focus-cmd)))
+              ((and (= typ "keyword") (= val "empty"))
+                (do (adv!) (parse-empty-cmd)))
+              ((and (= typ "keyword") (= val "clear"))
+                (do (adv!) (parse-empty-cmd)))
+              ((and (= typ "keyword") (= val "swap"))
+                (do (adv!) (parse-swap-cmd)))
               (true (parse-expr))))))
       (define
         parse-cmd-list
@@ -1548,7 +1597,10 @@
                 (= v "scroll")
                 (= v "select")
                 (= v "reset")
-                (= v "focus"))))
+                (= v "focus")
+                (= v "empty")
+                (= v "clear")
+                (= v "swap"))))
           (define
             cl-collect
             (fn
@@ -1578,7 +1630,7 @@
           (let
             ((every? (match-kw "every")))
             (let
-              ((event-name (let ((v (tp-val))) (adv!) v)))
+              ((event-name (parse-compound-event-name)))
               (let
                 ((flt (if (= (tp-type) "bracket-open") (do (adv!) (let ((f (parse-expr))) (if (= (tp-type) "bracket-close") (adv!) nil) f)) nil)))
                 (let