feat: real dates and per-account detail in every statement export

Every statement export rendered life-of-ledger totals under whatever date
range or as-of label was asked for, and the P&L and balance sheet XLSX
were totals-only. Now:

- books.profit_and_loss / books.balance_sheet and the csv, json, xlsx,
  pdf exports and CPA package all use core's profit_and_loss_for_period
  and balance_sheet_as_of, with a line per account. The tools keep their
  totals and add revenue/expense/asset/liability/equity account lines.
  An omitted start is the first posted entry, never "0001-01-01".
- ledger-import::report lays a statement out once (section, line,
  subtotal, total) for every renderer, with one exact amount formatter:
  thousands separators, negatives in parentheses, no floats. XLSX keeps
  numeric cells with an accounting number format, named sheets, company
  header, totals with borders; the trial balance gains its totals row.
- ledger-mcp reads wanderbooks.toml (next to --data-dir, or
  --books-toml): company name for headers, fiscal_year_start for the CPA
  package's fiscal year to date (end derived; Feb 29 rejected), and
  [books] receipt_threshold, which the server had been ignoring.
  config.json's receipt_policy still wins when set. New dependency: toml
  1.x (already in the lockfile via another crate).
- Store::journal_seq(); every report notes the journal seq it reflects.

Tests: company.rs unit tests (fiscal years incl. a July start, scaffold
parsing, bad settings); report.rs formatting tests; an MCP stdio test with
--books-toml (threshold 5.00 enforced, February-only P&L with account
lines, start defaults to the first entry, as-of balance sheet).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu

crates/ledger-mcp/tests/mcp_stdio.rs

@@ -15,10 +15,15 @@ struct Mcp {
 
 impl Mcp {
     fn spawn(data_dir: &std::path::Path) -> Self {
+        Self::spawn_with(data_dir, &[])
+    }
+
+    fn spawn_with(data_dir: &std::path::Path, extra: &[&std::ffi::OsStr]) -> Self {
         let bin = env!("CARGO_BIN_EXE_ledger-mcp");
         let mut child = Command::new(bin)
             .arg("--data-dir")
             .arg(data_dir)
+            .args(extra)
             .stdin(Stdio::piped())
             .stdout(Stdio::piped())
             .stderr(Stdio::null())
@@ -878,3 +883,99 @@ fn mcp_statement_pdfs_and_cpa_package_over_stdio() {
     std::io::Read::read_to_end(&mut zip.by_name("cash-flow.pdf").unwrap(), &mut cf).unwrap();
     assert!(cf.starts_with(b"%PDF"));
 }
+
+#[test]
+fn mcp_period_statements_over_stdio() {
+    let dir = test_dir("period-statements");
+    // A rejected receipt policy would show up as a failed post below: the
+    // toml lowers the threshold from 25.00 to 5.00.
+    let toml = dir.join("wanderbooks.toml");
+    std::fs::write(
+        &toml,
+        "[company]\nname = \"Test Co\"\nfiscal_year_start = \"02-01\"\n[books]\nreceipt_threshold = \"5.00\"\n",
+    )
+    .unwrap();
+    let data = dir.join("books-data");
+    let mut mcp = Mcp::spawn_with(
+        &data,
+        &[std::ffi::OsStr::new("--books-toml"), toml.as_os_str()],
+    );
+    mcp.request(
+        "initialize",
+        json!({
+            "protocolVersion": "2025-06-18",
+            "capabilities": {},
+            "clientInfo": {"name": "smoke-test", "version": "0.1.0"},
+        }),
+    );
+    mcp.notify("notifications/initialized");
+    mcp.call(
+        "books.import_chart_csv",
+        json!({"csv_text": "code,name,type,parent_code\n1000,Cash,asset,\n3000,Capital,equity,\n4000,Sales,revenue,\n6000,Software,expense,\n"}),
+    );
+    let mut post = |mcp: &mut Mcp, date: &str, dr: &str, cr: &str, amount: &str| {
+        let e = mcp.call(
+            "books.draft_entry",
+            json!({"date": date, "description": "x"}),
+        );
+        let id = e["entry_id"].as_u64().unwrap();
+        mcp.call(
+            "books.add_line",
+            json!({"entry_id": id, "account": dr, "side": "debit", "amount": amount}),
+        );
+        mcp.call(
+            "books.add_line",
+            json!({"entry_id": id, "account": cr, "side": "credit", "amount": amount}),
+        );
+        id
+    };
+    let id = post(&mut mcp, "2026-01-02", "1000", "3000", "1000.00");
+    // 1000.00 > 5.00 (the toml threshold): a receipt is required.
+    let err = mcp.call_err(
+        "books.post_entry",
+        json!({"entry_id": id, "confirmed": true}),
+    );
+    assert!(err.contains("5.00"), "{err}");
+    mcp.call(
+        "books.attach_receipt",
+        json!({"entry_id": id, "file_name": "r.pdf", "mime_type": "application/pdf",
+               "content_base64": base64_like(b"r")}),
+    );
+    mcp.call(
+        "books.post_entry",
+        json!({"entry_id": id, "confirmed": true}),
+    );
+    for (date, dr, cr, amt) in [
+        ("2026-01-20", "1000", "4000", "4.00"),
+        ("2026-02-05", "6000", "1000", "3.00"),
+        ("2026-02-09", "1000", "4000", "2.50"),
+    ] {
+        let id = post(&mut mcp, date, dr, cr, amt);
+        mcp.call(
+            "books.post_entry",
+            json!({"entry_id": id, "confirmed": true}),
+        );
+    }
+
+    // February only: 2.50 sales, 3.00 software.
+    let feb = mcp.call(
+        "books.profit_and_loss",
+        json!({"start": "2026-02-01", "end": "2026-02-28"}),
+    );
+    assert_eq!(feb["revenue"], "2.50");
+    assert_eq!(feb["expenses"], "3.00");
+    assert_eq!(feb["net_income"], "-0.50");
+    assert_eq!(feb["expense_accounts"][0]["code"], "6000");
+    assert_eq!(feb["expense_accounts"][0]["amount"], "3.00");
+    // No start: the statement begins at the first entry, not year 1.
+    let all = mcp.call("books.profit_and_loss", json!({"end": "2026-02-28"}));
+    assert_eq!(all["start"], "2026-01-02");
+    assert_eq!(all["revenue"], "6.50");
+
+    // As of Jan 31: cash 1,004.00 = capital 1,000.00 + earnings 4.00.
+    let jan = mcp.call("books.balance_sheet", json!({"as_of": "2026-01-31"}));
+    assert_eq!(jan["assets"], "1004.00");
+    assert_eq!(jan["current_earnings"], "4.00");
+    assert_eq!(jan["equity_accounts"][0]["amount"], "1000.00");
+    assert_eq!(jan["balanced"], true);
+}