blogimport: Q-M4 live source — internal-data query adapter (75/75)

source.sx: live-source adapter resolving Q-M4 (internal-data query, not direct PG).
Injected fetch-fn transport port (hexagonal seam); parse-row maps a blog post-row to
the importer post dict and parses the :lexical JSON string via dream-json-parse.
End-to-end drivers: backfill! (enumerate->fetch->import) and sync-verify
(enumerate->fetch->verify), + backfill-ids! explicit-id fallback.

Tests mock the transport against the documented response contract incl. a real lexical
JSON string. README flags the one blog-side gap (add a published-posts enumeration
query) + production fetch_data wiring (lives in lib/host). source 20/20; total 75/75.

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

lib/blogimport/conformance.sh

@@ -16,7 +16,7 @@ if [ ! -x "$SX_SERVER" ]; then
   fi
 fi
 
-SUITES=(lexical import verify)
+SUITES=(lexical import verify source)
 
 OUT_JSON="lib/blogimport/scoreboard.json"
 OUT_MD="lib/blogimport/scoreboard.md"
@@ -49,9 +49,11 @@ run_suite() {
 (load "lib/content/callout.sx")
 (load "lib/content/media.sx")
 (load "lib/content/store.sx")
+(load "lib/dream/json.sx")
 (load "lib/blogimport/lexical.sx")
 (load "lib/blogimport/import.sx")
 (load "lib/blogimport/verify.sx")
+(load "lib/blogimport/source.sx")
 (epoch 2)
 (eval "(define bi-test-pass 0)")
 (eval "(define bi-test-fail 0)")