Add libproxyprotocol to the Debian, Rocky, and Alpine build environments

Upstream ships only a Makefile with no install target, so each image
compiles src/proxy_protocol.c with -fPIC, archives it into
libproxyprotocol.a, and installs the header manually, matching this
project's static-PIC-library convention.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016Xj6cCTEVsr5PM43uTsbq8

alpine3.24/Dockerfile

@@ -644,6 +644,16 @@ RUN curl --fail --location --output jemalloc.tar.gz \
     && cd .. \
     && rm -rf src
 
+RUN curl --fail --location --output libproxyprotocol.tar.gz \
+        https://wangguofang.net/github.com/kosmas-valianos/libproxyprotocol/archive/v1.3.3.tar.gz \
+    && mkdir src \
+    && tar --extract --gzip --file=libproxyprotocol.tar.gz --directory=src --strip-components=1 \
+    && rm libproxyprotocol.tar.gz \
+    && gcc -fPIC -c -o src/src/proxy_protocol.o src/src/proxy_protocol.c \
+    && ar rcs /usr/local/lib/libproxyprotocol.a src/src/proxy_protocol.o \
+    && cp src/src/proxy_protocol.h /usr/local/include/ \
+    && rm -rf src
+
 RUN curl --fail --location --output makeself.tar.gz \
         https://wangguofang.net/github.com/megastep/makeself/archive/release-2.7.1.tar.gz \
     && mkdir src \