P2 slice 8: the viewer's menu, setup, no confinement (D-32)

No Landlock, no seccomp, no helper: isolation is "same_user
(advisory)". The lease socket keeps two intents (close, format-upgrade
consent). The viewer holds the books open while it runs and gains a
Books menu: New books, Back up now, Restore (preview, then confirm),
Close, Connect Claude Code / Codex. New commands `wanderbooks books
back-up` and `wanderbooks connect claude|codex`. The scaffold
(`new`/`init` and its templates) is gone; install.sh needs no sudo.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T3gXMVt7XJPi6ens1or9Dj

docs/spec/rules.md

@@ -906,7 +906,6 @@ checked to change no figure or entry; `approval_rules_off_by_default`,
 `a_newer_key_or_kind_is_newer`;
 `books_written_under_p1_open_to_their_record`, fixture
 `old-books/p1_record`); `ledger-config` `tests/codec_props.rs`
-(`exports_round_trip`) and codec unit tests; `ledger-cli` `tests/init.rs`
-`the_toml_and_its_examples_import_and_round_trip`; `ledger-mcp`
+(`exports_round_trip`) and codec unit tests; `ledger-mcp`
 `tests/spec_kept.rs`; Lean `Step.record_changes_no_figure`,
 `Reachable.records`; fuzz `fuzz_settings_replay`.