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>

blog/sx/handlers/link-card.sx

@@ -0,0 +1,31 @@
+;; Blog link-card fragment handler
+;;
+;; Renders link-card(s) for blog posts by slug.
+;; Supports single mode (?slug=x) and batch mode (?keys=x,y,z).
+
+(defhandler link-card (&key slug keys)
+  (if keys
+    (let ((slugs (split keys ",")))
+      (<> (map (fn (s)
+        (let ((post (query "blog" "post-by-slug" :slug (trim s))))
+          (when post
+            (<> (str "<!-- fragment:" (trim s) " -->")
+                (~link-card
+                  :link (app-url "blog" (str "/" (get post "slug") "/"))
+                  :title (get post "title")
+                  :image (get post "feature_image")
+                  :icon "fas fa-file-alt"
+                  :subtitle (or (get post "custom_excerpt") (get post "excerpt"))
+                  :detail (get post "published_at_display")
+                  :data-app "blog"))))) slugs)))
+    (when slug
+      (let ((post (query "blog" "post-by-slug" :slug slug)))
+        (when post
+          (~link-card
+            :link (app-url "blog" (str "/" (get post "slug") "/"))
+            :title (get post "title")
+            :image (get post "feature_image")
+            :icon "fas fa-file-alt"
+            :subtitle (or (get post "custom_excerpt") (get post "excerpt"))
+            :detail (get post "published_at_display")
+            :data-app "blog"))))))

blog/sx/handlers/nav-tree.sx

@@ -0,0 +1,80 @@
+;; Blog nav-tree fragment handler
+;;
+;; Renders the full scrollable navigation menu bar with app icons.
+;; Uses nav-tree I/O primitive to fetch menu nodes from the blog DB.
+
+(defhandler nav-tree (&key app_name path)
+  (let ((app       (or app_name ""))
+        (cur-path  (or path "/"))
+        (first-seg (first (filter (fn (s) (not (empty? s)))
+                            (split (trim cur-path) "/"))))
+        (items     (nav-tree))
+        (nav-cls   "whitespace-nowrap flex items-center gap-2 rounded p-2 text-sm")
+
+        ;; App slug → URL mapping
+        (app-slugs (dict
+          :cart     (app-url "cart" "/")
+          :market   (app-url "market" "/")
+          :events   (app-url "events" "/")
+          :federation (app-url "federation" "/")
+          :account  (app-url "account" "/")
+          :artdag   (app-url "artdag" "/"))))
+
+    (let ((item-sxs
+            (<>
+              ;; Nav items from DB
+              (map (fn (item)
+                (let ((item-slug (or (get item "slug") ""))
+                      (href (or (get app-slugs item-slug)
+                                (app-url "blog" (str "/" item-slug "/"))))
+                      (selected (or (= item-slug (or first-seg ""))
+                                    (= item-slug app))))
+                  (~blog-nav-item-link
+                    :href href
+                    :hx-get href
+                    :selected (if selected "true" "false")
+                    :nav-cls nav-cls
+                    :img (~img-or-placeholder
+                           :src (get item "feature_image")
+                           :alt (or (get item "label") item-slug)
+                           :size-cls "w-8 h-8 rounded-full object-cover flex-shrink-0")
+                    :label (or (get item "label") item-slug)))) items)
+
+              ;; Hardcoded artdag link
+              (~blog-nav-item-link
+                :href (app-url "artdag" "/")
+                :hx-get (app-url "artdag" "/")
+                :selected (if (or (= "artdag" (or first-seg ""))
+                                  (= "artdag" app)) "true" "false")
+                :nav-cls nav-cls
+                :img (~img-or-placeholder
+                       :src nil :alt "art-dag"
+                       :size-cls "w-8 h-8 rounded-full object-cover flex-shrink-0")
+                :label "art-dag")))
+
+          ;; Scroll wrapper IDs + hyperscript
+          (arrow-cls    "scrolling-menu-arrow-menu-items-container")
+          (cid          "menu-items-container")
+          (left-hs      (str "on click set #" cid ".scrollLeft to #" cid ".scrollLeft - 200"))
+          (scroll-hs    (str "on scroll "
+                             "set cls to '" arrow-cls "' "
+                             "set arrows to document.getElementsByClassName(cls) "
+                             "set show to (window.innerWidth >= 640 and "
+                             "my.scrollWidth > my.clientWidth) "
+                             "repeat for arrow in arrows "
+                             "if show remove .hidden from arrow add .flex to arrow "
+                             "else add .hidden to arrow remove .flex from arrow end "
+                             "end"))
+          (right-hs     (str "on click set #" cid ".scrollLeft to #" cid ".scrollLeft + 200")))
+
+      (if (empty? items)
+        (~blog-nav-empty :wrapper-id "menu-items-nav-wrapper")
+        (~scroll-nav-wrapper
+          :wrapper-id "menu-items-nav-wrapper"
+          :container-id cid
+          :arrow-cls arrow-cls
+          :left-hs left-hs
+          :scroll-hs scroll-hs
+          :right-hs right-hs
+          :items item-sxs
+          :oob true)))))

blog/sx/sx_components.py

@@ -28,8 +28,8 @@ from shared.sx.helpers import (
     full_page_sx,
 )
 
-# Load blog service .sx component definitions
-load_service_components(os.path.dirname(os.path.dirname(__file__)))
+# Load blog service .sx component definitions + handler definitions
+load_service_components(os.path.dirname(os.path.dirname(__file__)), service_name="blog")
 
 
 def _ctx_csrf(ctx: dict) -> str: