feat(ui): Add React based UI for the vibes at /app

This adds a completely separate frontend based on React because I
found that code gen works better with React once the application gets
bigger. In particular it was getting very hard to move past add
connectors and actions.

The idea is to replace the standard UI with this once it has been
tested. But for now it is available at /app in addition to the
original at /

Signed-off-by: Richard Palethorpe <io@richiejp.com>

Dockerfile.webui

@@ -1,6 +1,24 @@
 # Define argument for linker flags
 ARG LDFLAGS=-s -w
 
+# Use Bun container for building the React UI
+FROM oven/bun:1 as ui-builder
+
+# Set the working directory for the React UI
+WORKDIR /app
+
+# Copy package.json and bun.lockb (if exists)
+COPY webui/react-ui/package.json webui/react-ui/bun.lockb* ./
+
+# Install dependencies
+RUN bun install --frozen-lockfile
+
+# Copy the rest of the React UI source code
+COPY webui/react-ui/ ./
+
+# Build the React UI
+RUN bun run build
+
 # Use a temporary build image based on Golang 1.22-alpine
 FROM golang:1.22-alpine as builder
 
@@ -23,6 +41,9 @@ RUN go mod download
 # Now copy the rest of the source code
 COPY . .
 
+# Copy the built React UI from the ui-builder stage
+COPY --from=ui-builder /app/dist /work/webui/react-ui/dist
+
 # Build the application
 RUN go build -ldflags="$LDFLAGS" -o localagent ./
 
@@ -33,6 +54,5 @@ COPY --from=builder /work/localagent /localagent
 COPY --from=builder /etc/ssl/ /etc/ssl/
 COPY --from=builder /tmp /tmp
 
-
 # Define the command that will be run when the container is started
 ENTRYPOINT ["/localagent"]