refactor(reader): extract.rs moves into ledger-reader (U0d)

D-61 (Q-9): the writer sheds the typesetter and the crate map is layered
again. The PDF/XLSX reader (extract.rs, plan P6) is now the plain library
crate ledger-reader, moved whole with git mv and no behavior change.
ledger-store depends on it instead of ledger-import, so the store no
longer builds Typst or the fonts; ledger-import re-exports it as
ledger_import::extract so gui, mcp, host and the fuzz targets compile
unchanged, and still never depends on the store. New crate carries only
the dependencies extract.rs imports (hayro, hayro-interpret, kurbo, zip,
quick-xml, thiserror); fuzz/Cargo.lock gains the new package.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HS8WZziDnyxunC23MUxrLp

crates/ledger-store/tests/attachments.rs

@@ -1471,8 +1471,8 @@ fn extraction_is_journaled_once_per_version() {
     let x = s.extraction(id).unwrap().expect("an extraction record");
     assert_eq!(x.status, ExtractionStatus::Ok);
     assert_eq!(x.pages, 1);
-    assert_eq!(x.extractor, ledger_import::extract::EXTRACTOR);
-    assert_eq!(x.version, ledger_import::extract::VERSION);
+    assert_eq!(x.extractor, ledger_reader::EXTRACTOR);
+    assert_eq!(x.version, ledger_reader::VERSION);
     assert_eq!(
         s.extraction_text(id).unwrap().as_deref(),
         Some(String::from_utf8_lossy(text).as_ref())