feat(package): one attention engine over PackageBooks (U0b)

Needs attention was computed by the viewer alone, while books.start
hand-picked a handful of next steps. The human's list and the agent's
could disagree, and a new item had to be written twice (or, as
books.start showed, not at all).

Move the engine to ledger-package over PackageBooks: one function,
find/find_with(books, today, settings, integrity), reads the ledger, the
journal's event types (an entry's origin), the attachments and their
links, the statements, the reconciliations, and the database check. The
viewer's attention module now only maps Target to Route; books.start
turns the same items into its next steps (why = the item's title, top 12),
so the list the human sees and the steps the agent gets cannot drift.

PackageBooks gains settings, journal, statements, reconciliations and
disk_check, implemented for Store and Snapshot, so both views answer
alike. The W-9, reconciliation and 1099 predicates move beside the items
to keep one copy. ledger-package gains ledger-config and serde_json (the
receipt policy and the tool arguments the items carry).

Tests: view_model.rs and spec_kept.rs pass unchanged; the new
attention_parity.rs compares the viewer and books.start item for item on
the demo books and on a book written entry by entry. just check green.

plan/served.md

@@ -1231,7 +1231,29 @@ Each unit follows the 8.0.4 template. "A-n" is an owner answer numbered in 8.3.1
 5. **Files:** owns `crates/ledger-package/src/attention.rs`, `crates/ledger-gui/src/attention.rs`; touches `crates/ledger-package/src/books.rs`, `crates/ledger-gui/src/books.rs`, `crates/ledger-mcp/src/tools/kept.rs`, `docs/architecture.md`.
 6. **Tests and proofs:** `crates/ledger-gui/tests/view_model.rs` passes unchanged (the viewer's list is the engine's); new `crates/ledger-cli/tests/attention_parity.rs::the_viewer_and_books_start_see_the_same_attention` (on the demo books and on a random book: the viewer's items equal the server's, item for item; pattern `projects_parity.rs`); the existing `spec_kept.rs` tests of `books.start` pass unchanged.
 7. **Done when:** (1) `ledger-gui` no longer computes any attention item itself; (2) `books.start` lists the same items the viewer shows, proven by the parity test; (3) `just check` green; (4) no new crate and no new trait beyond `PackageBooks`.
-8. **As built:** none yet.
+8. **As built (2026-10-26):**
+   - `PackageBooks` grew `journal`, `statements`, `reconciliations` and
+     `disk_check` beside `settings` (the Build named only `settings`): the
+     engine reads an entry's origin from the journal's event types (as the
+     viewer's builder did), and the viewer's statements, reconciliations
+     and database check, so a `Store` and a `Snapshot` answer alike.
+   - `Attention` keeps the viewer's `prompt` beside the plan's `kind` and
+     `tool`: the viewer draws the shared text and the server turns the same
+     item into a next step without a second copy of the prompts.
+   - `find_with` takes the viewer's already-computed `Integrity` (the
+     loader checks the database and the stored files once per refresh);
+     `find` computes it for callers with none.
+   - `books.start` lists at most 12 attention steps (the eventual
+     `needs_attention` top 12; counts by kind come with P5), each step's
+     `why` cut to 160 characters (a free-text description could otherwise
+     push the result past 8 KB), and passes `Integrity::default()`: the
+     server's own damage check is `books.verify`.
+   - The W-9 and reconciliation prompts and the 1099 predicate moved to
+     `ledger-package`; `pages/parties.rs`, `pages/reconciliation.rs` and
+     `Books::files_1099` delegate to them (two files beyond the Build's
+     list, to keep one copy of each text).
+   - `ledger-package` gained `ledger-config` and `serde_json` (the receipt
+     policy the items use, and the tool arguments they carry).
 
 #### U0c: testing notes for S1-B, S2, S3, and stale notes in the tool docs