Rewrite from Go + vanilla JS to Python (FastAPI) + React (TypeScript)

- Backend: Python 3.12 with FastAPI, SQLAlchemy, boto3
- Frontend: React 18 with TypeScript, Vite build tooling
- Updated Dockerfile for multi-stage Node + Python build
- Updated CI pipeline for Python backend
- Removed old Go code (cmd/, internal/, go.mod, go.sum)
- Updated README with new tech stack documentation

Dockerfile

@@ -1,39 +1,41 @@
-# Build stage
-FROM golang:1.22-alpine AS builder
+# Frontend build stage
+FROM node:20-alpine AS frontend-builder
 
-RUN apk add --no-cache git ca-certificates
+WORKDIR /app/frontend
 
-WORKDIR /app
+# Copy package files
+COPY frontend/package*.json ./
+RUN npm install
 
-# Copy go mod files
-COPY go.mod go.sum* ./
-RUN go mod download
+# Copy frontend source
+COPY frontend/ ./
 
-# Copy source code
-COPY . .
-
-# Build the binary
-RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build \
-    -ldflags="-w -s" \
-    -o /orchard-server \
-    ./cmd/orchard-server
+# Build frontend
+RUN npm run build
 
 # Runtime stage
-FROM alpine:3.19
+FROM python:3.12-slim
 
-RUN apk add --no-cache ca-certificates tzdata
+# Install system dependencies
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    curl \
+    && rm -rf /var/lib/apt/lists/*
 
 # Create non-root user
-RUN addgroup -g 1000 orchard && \
-    adduser -u 1000 -G orchard -s /bin/sh -D orchard
+RUN groupadd -g 1000 orchard && \
+    useradd -u 1000 -g orchard -s /bin/bash -m orchard
 
 WORKDIR /app
 
-# Copy binary from builder
-COPY --from=builder /orchard-server /app/orchard-server
+# Copy requirements and install Python dependencies
+COPY backend/requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
 
-# Copy migrations
-COPY --from=builder /app/migrations /app/migrations
+# Copy backend source
+COPY backend/ ./backend/
+
+# Copy frontend build
+COPY --from=frontend-builder /app/frontend/dist ./frontend/dist
 
 # Set ownership
 RUN chown -R orchard:orchard /app
@@ -43,6 +45,6 @@ USER orchard
 EXPOSE 8080
 
 HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
-    CMD wget --no-verbose --tries=1 --spider http://localhost:8080/health || exit 1
+    CMD curl -f http://localhost:8080/health || exit 1
 
-ENTRYPOINT ["/app/orchard-server"]
+CMD ["uvicorn", "backend.app.main:app", "--host", "0.0.0.0", "--port", "8080"]