fix: packaged SQLite bridge bindings for release builds

[Yashh56]

Summary

Fix the packaged SQLite bridge so release builds can load better-sqlite3 correctly.

Changes

• downgrade better-sqlite3 to 11.9.0 in the bridge
• add a packaging helper that fetches a Node 18-compatible better_sqlite3.node for the pkg bridge runtime
• keep local development working by re-enabling better-sqlite3 install/build scripts in bridge/pnpm-workspace.yaml
• make bridge packaging platform-aware for Windows and Linux
• update the release workflow to use Node 22 + pnpm 10 and rely on the fixed packaging path instead of the old inline
  bridge build logic
• update build docs to match the new packaging flow

Why

The packaged bridge runs on Node 18 via pkg, but the local SQLite native addon was being built for the host Node
version. That caused release builds to fail with missing or ABI-mismatched better_sqlite3.node bindings.

Verification

• pnpm --dir bridge rebuild better-sqlite3
• pnpm --dir bridge run build
• pnpm --dir bridge run copy:native
• cargo check --manifest-path src-tauri/Cargo.toml
• built a temporary packaged bridge and verified db.connectTest succeeds against a SQLite database under the
  packaged Node 18 runtime