Fix ZSTD linking with build script and clean debian/install

- Add build.rs to handle ZSTD library linking via pkg-config
- Add pkg-config as build dependency in Cargo.toml
- Clean debian/install to avoid conflicts with manual installation
- ZSTD linking now works properly for OpenSSL with ZSTD support
- Local Debian package build succeeds

Cargo.toml

@@ -49,6 +49,9 @@ widestring = "1.2.0"
 walkdir = "2.3.2"
 signal-hook-registry = "1.4.5"
 
+[build-dependencies]
+pkg-config = "0.3"
+
 [profile.release]
 # We assume we're being delivered via e.g. RPM which supports split debuginfo
 debug = true

build.rs

@@ -0,0 +1,9 @@
+fn main() {
+    // Link against ZSTD library since OpenSSL was compiled with ZSTD support
+    if pkg_config::Config::new().probe("libzstd").is_ok() {
+        println!("cargo:rustc-link-lib=zstd");
+    }
+    
+    // Re-run if build script changes
+    println!("cargo:rerun-if-changed=build.rs");
+}

debian/install

@@ -1,17 +1,5 @@
-# Binary files
-target/release/bootupd usr/libexec/
-
 # Systemd service
 systemd/bootloader-update.service usr/lib/systemd/system/
 
-# Documentation
-README.md usr/share/doc/deb-bootupd/
-deb-bootupd.md usr/share/doc/deb-bootupd/
-VERSION.md usr/share/doc/deb-bootupd/
-
 # Manual pages
 debian/man/bootupctl.1 usr/share/man/man1/
-
-# Man pages (if available)
-# debian/bootupd.1 usr/share/man/man1/
-# debian/bootupctl.1 usr/share/man/man1/