blogimport: published-posts source contract + blog-side draft (76/76)

source.sx refactored to a single published-posts batch query returning full rows
(incl. lexical) — the existing post-by-id/slug DTO lacks lexical (sx_content/html
only), so the canonical lexical->blocks path needs a dedicated migration provider.
backfill-ids! now filters client-side (no extra query).

drafts/published-posts.sx + drafts/README.md: paste-ready blog-app change (defquery +
SqlBlogService.list_published_posts returning rows incl. raw lexical). README updated.
source 21/21; total 76/76.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

lib/blogimport/tests/source.sx

@@ -5,7 +5,7 @@
 (content-bootstrap-callout!)
 (content-bootstrap-media!)
 
-; ---- canned service responses (lexical arrives as a JSON STRING, the DB column) ----
+; ---- canned service rows (lexical arrives as a JSON STRING, the DB column) ----
 (define
   lex1
   "{\"root\":{\"children\":[{\"type\":\"heading\",\"tag\":\"h2\",\"children\":[{\"type\":\"text\",\"text\":\"Live\"}]},{\"type\":\"paragraph\",\"children\":[{\"type\":\"text\",\"text\":\"from db\"}]}]}}")
@@ -19,16 +19,12 @@
    :lexical "{\"children\":[{\"type\":\"paragraph\",\"children\":[{\"type\":\"text\",\"text\":\"second\"}]}]}"})
 
 ; ---- mock transport: (fetch-fn query params) -> response ----
+; the `published-posts` migration query returns full rows (incl. lexical) in one batch.
 (define
   mock-fetch
   (fn (query params)
     (cond
-      ((equal? query "published-posts") (list "post-1" "post-2"))
-      ((equal? query "post-by-id")
-        (cond
-          ((equal? (get params :id) "post-1") row1)
-          ((equal? (get params :id) "post-2") row2)
-          (else nil)))
+      ((equal? query "published-posts") (list row1 row2))
       (else nil))))
 
 ; ---- parse-row maps fields + parses the lexical JSON string ----
@@ -49,8 +45,8 @@
 (bi-test "parse-row structured lexical used as-is"
   (map blk-type (blogimport/lex-blocks (get post3 :lexical))) (list "text"))
 
-; ---- enumeration + source-posts ----
-(bi-test "published-ids" (blogimport/published-ids mock-fetch) (list "post-1" "post-2"))
+; ---- source-rows / source-posts ----
+(bi-test "source-rows count" (len (blogimport/source-rows mock-fetch)) 2)
 (bi-test "source-posts ids"
   (map (fn (p) (get p :id)) (blogimport/source-posts mock-fetch))
   (list "post-1" "post-2"))
@@ -76,8 +72,9 @@
 (bi-test "sync-verify ok" (get sv :ok) 2)
 (bi-test "sync-verify no mismatch" (get sv :mismatched) (list))
 
-; ---- explicit-id fallback path (before the enumeration query lands) ----
+; ---- partial backfill: client-side id filter (no extra blog query) ----
 (define B2 (persist/open))
 (define covx (blogimport/backfill-ids! B2 mock-fetch (list "post-2") 10))
 (bi-test "backfill-ids imported" (get covx :imported) 1)
 (bi-test "backfill-ids post-2 ids" (doc-ids (content/head B2 "post-2")) (list "b0"))
+(bi-test "backfill-ids other not imported" (content/version-count B2 "post-1") 0)