feat: ledger-gui — a read-only, live desktop view of the books

egui/wgpu app for owners and their accountant: Overview, Cash, Profit,
Transactions (with rendered receipts and journal history), Reports
(statements with interval columns, comparisons, drill-down), Accounts,
Documents, Company, Journal; Ctrl+K palette; back/forward; light/dark.
Follows the journal live (~30 ms from write to screen). --demo opens a
deterministic demo company, also used for screenshot tests.

Engine: ledger-store Snapshot (read-only, incremental, tolerant of a
half-written tail); ledger-core analysis (intervals, balance series,
P&L by interval, cash flows); ledger-config extracted from ledger-mcp
with the full company profile and cash_accounts.

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

plan/roadmap.md

@@ -31,7 +31,9 @@ The primary interface is MCP, not a cloned GUI (Stephen's call, 2026-10-10).
 - Done when: a fixture book produces byte-identical snapshots from both
   engines with zero manual steps.
 
-## Phase 4 — Read-only GUI
+## Phase 4 — Read-only GUI (first version done, 2026-10-12)
+
+`ledger-gui`: see `plan/gui.md` for the design and what's built.
 
 - Consumes the `ledger-store` event log: live updates — the answer to
   "watch its files to update live."