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

docker/Dockerfile

@@ -0,0 +1,14 @@
+FROM nimlang/nim:1.6.4-ubuntu
+
+RUN apt-get update -yqq \
+    && apt-get install -y --no-install-recommends \
+               libsass-dev \
+               sqlite3 \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+COPY . /app
+
+# install dependencies
+RUN nimble install -Y