feat: Enhance Docker build versioning with a build argument, fetch git tags during deployment, and add comprehensive deployment documentation.

Dockerfile

@@ -14,14 +14,22 @@ RUN npm ci
 FROM base AS builder
 WORKDIR /app
 
+# Accept version as build argument (optional)
+ARG APP_VERSION=""
+
 # Install git to extract version information
 RUN apk add --no-cache git
 
 COPY --from=deps /app/node_modules ./node_modules
 COPY . .
 
-# Extract version from git
-RUN git describe --tags --always 2>/dev/null > /tmp/version.txt || echo "unknown" > /tmp/version.txt
+# Extract version: use build arg if provided, otherwise get from git
+RUN if [ -n "$APP_VERSION" ]; then \
+    echo "$APP_VERSION" > /tmp/version.txt; \
+    else \
+    git describe --tags --always 2>/dev/null > /tmp/version.txt || echo "unknown" > /tmp/version.txt; \
+    fi && \
+    echo "Building version: $(cat /tmp/version.txt)"
 
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