fix: Alpine parliament Docker build (musl clean rebuild)

Ignore/clean host objects, add linux-headers, and include sys/time.h
so discover builds under musl. Docker chair↔member handshake now passes.

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/Dockerfile.parliament

@@ -1,10 +1,11 @@
 # Build inside Alpine so the binary does not depend on the host Nix store.
 FROM alpine:latest AS build
-RUN apk add --no-cache build-base curl-dev ncurses-dev pkgconf python3
+RUN apk add --no-cache build-base curl-dev ncurses-dev pkgconf python3 \
+      linux-headers
 WORKDIR /src
 COPY . .
-# Skip WebUI asset embedding quirks in minimal images if needed; keep default on.
-RUN make -j"$(nproc)" cst-agent
+# Drop any host objects that slipped past .dockerignore (Nix glibc ≠ musl).
+RUN make clean && make -j"$(nproc)" cst-agent
 
 FROM alpine:latest
 RUN apk add --no-cache libcurl ncurses-libs ca-certificates