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

crates/ledger-cli/src/main.rs

@@ -169,6 +169,8 @@ fn print_usage() {
 /// A binary next to this one (cargo installs them side by side), else on
 /// the PATH.
 fn find_binary(name: &str) -> Option<PathBuf> {
+    let name = format!("{name}{}", env::consts::EXE_SUFFIX);
+    let name = name.as_str();
     if let Some(dir) = env::current_exe()
         .ok()
         .and_then(|e| e.parent().map(Path::to_path_buf))