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/scoreboard.md

@@ -0,0 +1,10 @@
+# blogimport Conformance Scoreboard
+
+_Generated by `lib/blogimport/conformance.sh`_
+
+| Suite | Pass | Fail | Total |
+|-------|-----:|-----:|------:|
+| lexical | 23 | 0 | 23 |
+| import | 21 | 0 | 21 |
+| verify | 11 | 0 | 11 |
+| **Total** | **55** | **0** | **55** |