Add macros, declarative handlers (defhandler), and convert all fragment routes to sx

Phase 1 — Macros: defmacro + quasiquote syntax (`, ,, ,@) in parser,
evaluator, HTML renderer, and JS mirror. Macro type, expansion, and
round-trip serialization.

Phase 2 — Expanded primitives: app-url, url-for, asset-url, config,
format-date, parse-int (pure); service, request-arg, request-path,
nav-tree, get-children (I/O); jinja-global, relations-from (pure).
Updated _io_service to accept (service "registry-name" "method" :kwargs)
with auto kebab→snake conversion. DTO-to-dict now expands datetime fields
into year/month/day convenience keys. Tuple returns converted to lists.

Phase 3 — Declarative handlers: HandlerDef type, defhandler special form,
handler registry (service → name → HandlerDef), async evaluator+renderer
(async_eval.py) that awaits I/O primitives inline within control flow.
Handler loading from .sx files, execute_handler, blueprint factory.

Phase 4 — Convert all fragment routes: 13 Python fragment handlers across
8 services replaced with declarative .sx handler files. All routes.py
simplified to uniform sx dispatch pattern. Two Jinja HTML handlers
(events/container-cards, events/account-page) kept as Python.

New files: shared/sx/async_eval.py, shared/sx/handlers.py,
shared/sx/tests/test_handlers.py, plus 13 handler .sx files under
{service}/sx/handlers/. MarketService.product_by_slug() added.

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

market/sx/handlers/container-nav.sx

@@ -0,0 +1,21 @@
+;; Market container-nav fragment handler
+;;
+;; Renders marketplace link nav items for blog post pages.
+
+(defhandler container-nav (&key container_type container_id post_slug)
+  (let ((ct       (or container_type "page"))
+        (cid      (parse-int (or container_id "0")))
+        (slug     (or post_slug ""))
+        (markets  (service "market" "marketplaces-for-container"
+                    :container-type ct :container-id cid)))
+    (when (not (empty? markets))
+      (let ((styles       (or (jinja-global "styles") (dict)))
+            (nav-class    (or (get styles "nav_button") ""))
+            (sel-colours  (or (jinja-global "select_colours") "")))
+        (<> (map (fn (m)
+          (let ((href (app-url "market" (str "/" slug "/" (get m "slug") "/"))))
+            (~market-link-nav
+              :href href
+              :name (get m "name")
+              :nav-class nav-class
+              :select-colours sel-colours))) markets))))))

market/sx/handlers/link-card.sx

@@ -0,0 +1,42 @@
+;; Market link-card fragment handler
+;;
+;; Renders product preview card(s) by slug.
+;; Supports single mode (?slug=x) and batch mode (?keys=x,y,z).
+
+(defhandler link-card (&key slug keys)
+  (if keys
+    (let ((slugs (filter (fn (s) (not (empty? s)))
+                   (map trim (split keys ",")))))
+      (<> (map (fn (s)
+        (let ((product (service "market" "product-by-slug" :slug s)))
+          (<> (str "<!-- fragment:" s " -->")
+              (when (not (nil? product))
+                (let ((link (app-url "market" (str "/product/" (get product "slug") "/")))
+                      (subtitle (or (get product "brand") ""))
+                      (detail (if (get product "special_price")
+                                (str (get product "regular_price") " → " (get product "special_price"))
+                                (if (get product "regular_price")
+                                  (str (get product "regular_price"))
+                                  ""))))
+                  (~link-card
+                    :title (get product "title")
+                    :image (get product "image")
+                    :subtitle subtitle
+                    :detail detail
+                    :link link)))))) slugs)))
+    (when slug
+      (let ((product (service "market" "product-by-slug" :slug slug)))
+        (when (not (nil? product))
+          (let ((link (app-url "market" (str "/product/" (get product "slug") "/")))
+                (subtitle (or (get product "brand") ""))
+                (detail (if (get product "special_price")
+                          (str (get product "regular_price") " → " (get product "special_price"))
+                          (if (get product "regular_price")
+                            (str (get product "regular_price"))
+                            ""))))
+            (~link-card
+              :title (get product "title")
+              :image (get product "image")
+              :subtitle subtitle
+              :detail detail
+              :link link)))))))

market/sx/sx_components.py

@@ -22,8 +22,9 @@ from shared.sx.helpers import (
     full_page_sx, oob_page_sx,
 )
 
-# Load market-specific .sx components at import time
-load_service_components(os.path.dirname(os.path.dirname(__file__)))
+# Load market-specific .sx components + handlers at import time
+load_service_components(os.path.dirname(os.path.dirname(__file__)),
+                        service_name="market")
 
 
 # ---------------------------------------------------------------------------