Initial commit: nimforum with BaraDB backend

- Replaced SQLite with BaraDB via TCP wire protocol
- Added baradb_client.nim and baradb_sqlite.nim adapter
- Renamed SQL keywords: status->usrStatus, key->sessionKey, like->postLike
- Added NOW() support for datetime defaults
- Switched Jester to asynchttpserver (-d:useStdLib) to avoid thread/GC issues
- Frontend built and favicon added

.gitignore

@@ -0,0 +1,23 @@
+# Wildcard patterns.
+*.swp
+nimcache/
+*.db*
+
+# Specific paths
+/createdb
+/forum
+/nimforum.db
+
+# Binaries
+forum
+createdb
+editdb
+
+.vscode
+forum.json*
+browsertester
+setup_nimforum
+buildcss
+nimforum.css
+
+/src/frontend/forum.js