refactor!: one way to serve books: the stdio server is gone (D-44)

The owner (2026-10-23): "We should probably just delete the stdio path
altogether. THere's no point in that. And it sitting there unused will
just lead to bitrot. Nuke it?"

Books are served only by the books server (`wanderbooks server`),
reached by agents through the bridge (`wanderbooks mcp --book ID`),
which stays.

Removed: `wanderbooks dev-stdio`, the `ledger-mcp` binary, and
`ledger_mcp::run` (stdio and `--http` over a bare data dir), with all
that only that mode had:
- files the books make coming back inline: `HandedFile.content_base64`
  is gone, and `download` and `expires_at` are always there;
- books with no access log or backups: `books.access_log`,
  `books.backup` and `books.back_up_now` are always offered, by scope;
- the settings file read and reloaded (`legacy_files`), the vault key
  named by a file or `--vault-key-file`, and the books dir's
  key-inside-the-books and git checks (with `paths.rs`);
- `wire.rs` (the bridge frames an agent's lines itself);
- `books.settings`' file fields and `books.start`'s `settings_source`.

`BooksServer` is built one way, from `Served` (a book as the books
server serves it), in production and in the unit tests. An unknown tool
is now a protocol error (mcp-tools.md). Inline file input is unchanged.

Then the owner's three decisions (2026-10-23, the question tool):
(a) `books.import_settings` is removed entirely (118 tools): old books
come in whole by `wanderbooks books adopt`, which reads their settings
file once; ledger-config keeps its settings-file parsing only as far as
adoption uses it (`load` and the path-reading `effective_receipt_policy`
are gone), and `books.chart_template` gives its settings as
`books.set_setting` changes. (b) The viewer's loose-books-folder mode is
removed (`--data-dir`, `--books-toml`, `--vault-key-file`, the settings
file and config.json followed): it opens only books of the data root,
reading settings from the journal and the vault from the book's own
`vault/` and `keys/`. (c) `wanderbooks dev-stdio` has no stub: it is an
unknown command like any other word. Also: an upload's expiry past the
calendar is an error, never an empty string.

Tests: every suite that drove the stdio server moved to
crates/ledger-cli/tests/ and drives a real `wanderbooks server` on a
data root of its own (tests/common), handed files by their download;
mcp_stdio.rs is mcp_journeys.rs. Tests of what is gone are deleted and
listed in docs/testing.md. Docs: plan D-44 (D-18 superseded), STATUS,
testing, rules, mcp-interface, the handbook, README; justfile recipes.

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

bookspec/README.md

@@ -352,7 +352,7 @@ answers is refused, never skipped.
 | `register_row` | `asset`, `as_of` | the asset's row of the fixed asset register (B-15 rules 7 and 8, B-24): `acquired`, `in_service` (`YYYY-MM-DD`), `cost`, `accumulated_scheduled` (the schedule's), `accumulated_posted` (what the books carry), `unposted` (the one less the other), `book_value` (cost less posted), each `"0.00"` once disposed; the example names the figures it shows; an asset acquired after the day is refused | `ledger-core` `tests/bookspec.rs` |
 | `register_totals` | `as_of` | the register's totals over the assets held (B-24, B-25): `total_cost`, `total_accumulated_scheduled`, `total_accumulated_posted`, `total_book_value`, `total_depreciable_basis`, `total_tax_basis_723`, `missing_basis` (a count), and how it ties to the books: `unregistered_cost`, `unposted_depreciation`, `unattributed_accumulated`; the example names the figures it shows | `ledger-core` `tests/bookspec.rs` |
 | `asset_basis` | `asset`, no dates | the asset's basis facts and the tax figures they give (B-25): `rule`, `contributor_adjusted_basis`, `fmv_at_contribution`, `tax_basis_723`, `depreciable_basis`, `built_in_gain_704c` (a loss negative), each `"none"` where it has none, and `sec704c_1c` (`"true"` for a built-in loss, which counts only for the contributor); the example names the figures it shows | `ledger-core` `tests/bookspec.rs` |
-| `project` | `project`, `from`, `to` | the project's figures (B-37), every one given: `revenue`, `expenses` and `net` for the period (the revenue and expense lines tagged to it, closes left out), `to_date.revenue`, `to_date.expenses` and `to_date.net` (every tagged line through `to`), and `unrecovered_cost` (expenses less revenue to date, never below zero; `"none"` unless it is on spec) | `ledger-core` `tests/bookspec.rs`; `ledger-mcp` `project_figures_match_profit_and_loss_by_class` |
+| `project` | `project`, `from`, `to` | the project's figures (B-37), every one given: `revenue`, `expenses` and `net` for the period (the revenue and expense lines tagged to it, closes left out), `to_date.revenue`, `to_date.expenses` and `to_date.net` (every tagged line through `to`), and `unrecovered_cost` (expenses less revenue to date, never below zero; `"none"` unless it is on spec) | `ledger-core` `tests/bookspec.rs`; `ledger-cli` `tests/spec_projects.rs` `project_figures_match_profit_and_loss_by_class` |
 | `schedule_plan` | `schedule`, no dates | the schedule's plan (B-16): what it recognizes at each month end named (`"YYYY-MM-DD"`), `"0.00"` at one it doesn't post; `total`, all it recognizes; the example names the figures it shows | `ledger-core` `tests/bookspec.rs` |
 | `iif_lines` | `as_of` | formats appendix: the file's lines in order, each its fields joined by tabs, without the CR LF that ends each | `ledger-package` `the_bookspec_iif_example_matches_the_engine` |
 | `iif_changes` | `as_of` | formats appendix: each text the file writes differently from the books, in file order, as `[what, books' text, file's text]` (the example's header gives `what`) | `ledger-package` `the_bookspec_iif_example_matches_the_engine` |