feat: end-to-end integrity checks with self-healing; website; installer and Windows fixes

Store::verify compares the whole SQLite projection, every table row for
row, against a fresh projection of the journal; verify_and_heal rebuilds a
drifted database (keeping the old file) at every server start and via the
new books.verify tool, which also re-hashes every blob. The GUI checks the
server's database read-only and every stored file, and shows the result.
rebuild() also drops stale WAL/SHM files.

site/: the wanderbooks website (just site, just publish). install.sh:
OS detection (Windows points to WSL2), C compiler and git checks,
WANDERBOOKS_REPO. Windows: no directory fsync off Unix; .exe-aware lookup.
Repo justfile: check, build, install, demo, site.

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

justfile

@@ -0,0 +1,46 @@
+# wanderbooks repo recipes. `just` lists them.
+
+set shell := ["bash", "-cu"]
+
+# List recipes
+default:
+    @just --list
+
+# Everything CI should check: format, clippy (zero warnings), tests
+check:
+    cargo fmt --all --check
+    cargo clippy --workspace --all-targets -- -D warnings
+    cargo test --workspace
+
+# Build the release binaries (CLI, MCP server, GUI)
+build:
+    cargo build --release -p ledger-cli -p ledger-mcp -p ledger-gui
+
+# Install the binaries from this checkout into ~/.cargo/bin
+install:
+    for c in ledger-cli ledger-mcp ledger-gui; do cargo install --locked --path crates/$c; done
+
+# Open the GUI on the demo company
+demo:
+    cargo run --release -p ledger-gui -- --demo
+
+# Regenerate the website's screenshots from the demo company
+site-shots:
+    #!/usr/bin/env bash
+    set -euo pipefail
+    tmp=$(mktemp -d)
+    SHOT_DIR="$tmp/light" SHOT_ONLY=overview,entry,pnl SHOT_ENTRY=249 cargo test -p ledger-gui --test screens
+    SHOT_DIR="$tmp/dark" SHOT_DARK=1 SHOT_ONLY=overview cargo test -p ledger-gui --test screens
+    for f in overview entry pnl; do cp "$tmp/light/$f.png" site/assets/; done
+    cp "$tmp/dark/overview.png" site/assets/overview-dark.png
+    rm -rf "$tmp"
+
+# Assemble the website in site/dist (index.html, install.sh, assets)
+site:
+    rm -rf site/dist && mkdir -p site/dist
+    cp site/index.html install.sh site/dist/
+    cp -r site/assets site/dist/
+
+# Publish the website: just publish user@host:/var/www/wanderbooks
+publish dest: site
+    rsync -av --delete site/dist/ "{{dest}}"