refactor: reorganize project structure and update configurations

- Move migrations/ to database/schema/ for clarity on database schema definitions
- Move sqlc.yaml to internal/database/ to group with database code
- Move static/ to cmd/server/static/ to co-locate with server
- Update all configuration files and documentation
- Follow Go project conventions for better organization

Dockerfile

@@ -15,12 +15,26 @@ COPY . .
 # Download dependencies
 RUN go mod tidy
 
+# Install Node.js and npm for Tailwind CSS building
+RUN apk add --no-cache nodejs npm
+
+# Copy package files and install npm dependencies
+COPY package*.json ./
+RUN npm install
+
+# Copy source code (after npm to avoid re-running npm install on code changes)
+COPY . .
+
 # Generate sqlc code
 RUN sqlc generate
 
 # Generate templ code
 RUN templ generate
 
+# Build Tailwind CSS and download htmx
+RUN npm run build:css:prod
+RUN npm run postinstall
+
 # Build the application
 RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o main ./cmd/server
 
@@ -33,8 +47,8 @@ WORKDIR /root/
 # Copy the binary from builder stage
 COPY --from=builder /app/main .
 
-# Copy migrations (if needed for initialization)
-COPY --from=builder /app/migrations ./migrations
+# Copy database schema (if needed for initialization)
+COPY --from=builder /app/database/schema ./database/schema
 
 # Copy templates
 COPY --from=builder /app/templates ./templates