M0: label local builds in --version, About and the package release (#1529)

A build compiled with PDFCRAFT_BUILD_LABEL=<label> shows "0.7.1 (<label>)"
in `pdfcraft --version`, `pdfcraft-cli --version`, Help > About and the
first log line (pdfcraft_engine::build_info). The version itself is
unchanged, so the update check, the MCP server info and the User-Agent
still carry the release version.

packaging/linux/package.sh puts the label in the file names
(pdfcraft-0.7.1-<label>-linux-x86_64.rpm) and makes the .rpm/.deb release
`1.<label>` (nfpm `release: ${RELEASE}`, 1 when unlabelled). rpm sorts
0.7.1-1.<label> after 0.7.1-1 and before 0.7.2-1, so a locally built
package upgrades over the installed release and the next release replaces
it. packaging/env.sh accepts only letters, digits and inner dots, which
are valid in both rpm and deb release fields.

Unlabelled builds are unchanged.

Made with Claude Code (Claude Opus 5.5, medium effort). It passes the
workspace quality gates (fmt, clippy, cargo test --workspace, xtask assets)
and was checked by hand on Fedora 44, but it has not been exhaustively
regression tested.

Co-authored-by: bmh129 <[email protected]>
Co-authored-by: Claude Opus 5.5 <[email protected]>

apps/pdfcraft-cli/src/main.rs

@@ -141,7 +141,7 @@ fn stdout_line(line: std::fmt::Arguments<'_>) -> Result<(), CliError> {
 }
 
 fn version() -> Result<(), CliError> {
-    stdout_line(format_args!("pdfcraft-cli {}", env!("CARGO_PKG_VERSION")))?;
+    stdout_line(format_args!("pdfcraft-cli {}", pdfcraft_engine::build_info::version()))?;
     stdout_line(format_args!("Discord: {}  (help and feedback)", pdfcraft_engine::links::DISCORD))?;
     stdout_line(format_args!("Web:     {}", pdfcraft_engine::links::APP_PAGE))?;
     stdout_line(format_args!("Source:  {}", pdfcraft_engine::links::GITHUB))?;

apps/pdfcraft/Cargo.toml

@@ -14,6 +14,8 @@ workspace = true
 ureq = { version = "3.4", default-features = false, features = ["rustls-no-provider", "_ring"] }
 rustls-native-certs = "0.8"
 pdfcraft-ui-egui = { workspace = true }
+# `build_info`: the version and compile-time build label for `--version` and the log.
+pdfcraft-engine = { workspace = true }
 # wgpu draws; OpenGL (glow) is the fallback when wgpu can't start on an old or unusual GPU or
 # driver (#461, #435, #392), and can be chosen with PDFCRAFT_RENDERER=gl.
 eframe = { workspace = true, features = ["default_fonts", "wgpu", "glow", "accesskit", "wayland", "x11", "persistence", "links"] }

apps/pdfcraft/src/main.rs

@@ -155,7 +155,7 @@ fn main() -> eframe::Result {
     while let Some(a) = args.next() {
         match a.as_str() {
             "--version" => {
-                println!("pdfcraft {}", env!("CARGO_PKG_VERSION"));
+                println!("pdfcraft {}", pdfcraft_engine::build_info::version());
                 return Ok(());
             }
             "--control" => control_file = args.next(),
@@ -175,7 +175,7 @@ fn main() -> eframe::Result {
     // Records logged until now are written to it first.
     if let (Some(logger), Some(dir)) = (logger, settings_dir()) {
         match logger.attach_dir(&dir.join("logs")) {
-            Ok(path) => log::info!("PdfCraft {}, log file {}", env!("CARGO_PKG_VERSION"), path.display()),
+            Ok(path) => log::info!("PdfCraft {}, log file {}", pdfcraft_engine::build_info::version(), path.display()),
             // Standard error only by now (`attach_dir` gave up on the file); unlike `eprintln!`, never panics.
             Err(e) => log::warn!("no log file: {e}"),
         }