blogimport: lexical->persist genesis-import + at-rest parity verifier (55/55)

Implements plans/migration/data-migration.md (the un-started long-pole) and the
data-layer half of slice-01-blog §4. Host-ops migration module composing
content-on-sx + persist public APIs; isolated from lib/host and lib/content.

- lexical.sx: Ghost lexical (as SX dicts) -> content block list, deterministic ids
- import.sx: genesis import into content:<id> op-log, idempotent, + postmeta stream
- verify.sx: replay-and-diff vs row-derived oracle (proves round-trip lossless)

Inline formatting flattens to plain text (Phase-5 runs swap-point isolated in
lex-inline-text); live Postgres source (Q-M4) + improved-converter re-import (Q-M5)
flagged in README. 55/55 conformance: lexical 23, import 21, verify 11.

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

lib/blogimport/tests/verify.sx

@@ -0,0 +1,57 @@
+; lib/blogimport/tests/verify.sx — shadow-diff at rest (round-trip parity)
+(st-bootstrap-classes!)
+(content-bootstrap-blocks!)
+(content-bootstrap-doc!)
+(content-bootstrap-callout!)
+(content-bootstrap-media!)
+
+(define
+  p1
+  {:id "post-1" :slug "hello" :title "Hello" :status "published"
+   :visibility "public" :tags (list "news") :authors (list "u1")
+   :lexical {:root {:children (list
+     {:type "heading" :tag "h2" :children (list {:type "text" :text "Title"})}
+     {:type "paragraph" :children (list
+       {:type "text" :text "plain "}
+       {:type "text" :text "bold" :format 1})}
+     {:type "list" :listType "number" :children (list
+       {:type "listitem" :children (list {:type "text" :text "one"})}
+       {:type "listitem" :children (list {:type "text" :text "two"})})}
+     {:type "image" :src "/c.png" :alt "cat"})}}})
+
+(define
+  px
+  {:id "post-x" :slug "ghost" :title "Ghost" :status "published"
+   :lexical {:children (list {:type "paragraph" :children (list {:type "text" :text "never imported"})})}})
+
+; ---- happy path: replayed == oracle ----
+(define B (persist/open))
+(blogimport/import-post! B p1 10)
+(define v1 (blogimport/verify-post B p1))
+(bi-test "verify ok" (get v1 :ok) true)
+(bi-test "verify block-ok" (get v1 :block-ok) true)
+(bi-test "verify meta-ok" (get v1 :meta-ok) true)
+
+; ---- oracle block model is what we expect (inline bold flattened) ----
+(define orc (blogimport/oracle p1))
+(bi-test "oracle types"
+  (get (get orc :blocks) :types) (list "heading" "text" "list" "image"))
+(bi-test "oracle contents"
+  (get (get orc :blocks) :contents) (list "Title" "plain bold" (list "one" "two") "/c.png"))
+
+; ---- corruption is DETECTED (op-log diverges from oracle) ----
+(content/commit! B "post-1" (op-update "b1" "text" "CORRUPTED") 100)
+(define v2 (blogimport/verify-post B p1))
+(bi-test "verify detects corruption" (get v2 :ok) false)
+(bi-test "verify corruption is block-level" (get v2 :block-ok) false)
+
+; ---- an un-imported post fails verification (empty replay vs non-empty oracle) ----
+(bi-test "unimported not ok" (get (blogimport/verify-post B px) :ok) false)
+
+; ---- verify-all coverage scoreboard ----
+(define B3 (persist/open))
+(blogimport/import-post! B3 p1 10)
+(define cov (blogimport/verify-all B3 (list p1 px)))
+(bi-test "verify-all total" (get cov :total) 2)
+(bi-test "verify-all ok count" (get cov :ok) 1)
+(bi-test "verify-all mismatched" (get cov :mismatched) (list "post-x"))