`bun add -g omniroute` (and any runtime that does not reliably run the
better-sqlite3 postinstall script) leaves the *.node binary undownloaded.
The `bindings()` loader then throws "Could not locate the bindings file"
BEFORE any DLOPEN happens, which the previous detector missed — the user
saw a generic 500 page instead of the friendly "Run npm rebuild
better-sqlite3" guide.
Extended isNativeSqliteLoadError() to recognise:
- "Could not locate the bindings file" (bindings module preflight)
- "Cannot find module 'better-sqlite3'" (package not even installed)
- code === "MODULE_NOT_FOUND" (Node loader fallback)
isNativeSqliteLoadError is now exported so tests can pin the contract; the
detector covers both the "wrong NODE_MODULE_VERSION" and "binary never
shipped" failure modes operators have hit in practice.
