feat(nbd): add --version flag with X.Y.Z+GitSha format [c24ee8]

build.rs captures the short git SHA at compile time via
`git rev-parse --short HEAD` and emits it as GIT_SHORT_SHA. Falls back
to "unknown" when git is unavailable (e.g. Nix sandboxed builds).

main.rs adds a VERSION const (`env!("CARGO_PKG_VERSION") + "+" + SHA`)
and passes it to clap's `version =` attribute, enabling both -V and
--version flags.

Example output: `nbd 0.1.0+8f4d25b`

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

nbd/README.md

@@ -220,6 +220,7 @@ cargo install --path .
 
 ```sh
 # From the nbd/ directory
+cargo run -- --version   # prints e.g. nbd 0.1.0+7e311d6
 cargo run -- init
 cargo run -- create --title "Test ticket" --priority 7 --type bug
 cargo run -- list

nbd/build.rs

@@ -0,0 +1,31 @@
+//! Build script for `nbd`.
+//!
+//! Captures the short git SHA at compile time and emits it as the
+//! `GIT_SHORT_SHA` environment variable, making it available via
+//! `env!("GIT_SHORT_SHA")` in the crate source.
+//!
+//! Falls back to `"unknown"` when git is unavailable (e.g. a clean Nix
+//! sandbox build where `.git/` is not present).
+
+fn main() {
+    // Capture the short git SHA at build time.
+    let sha = std::process::Command::new("git")
+        .args(["rev-parse", "--short", "HEAD"])
+        .output()
+        .ok()
+        .and_then(|o| {
+            if o.status.success() {
+                Some(o.stdout)
+            } else {
+                None
+            }
+        })
+        .and_then(|b| String::from_utf8(b).ok())
+        .map(|s| s.trim().to_string())
+        .unwrap_or_else(|| "unknown".to_string());
+
+    println!("cargo:rustc-env=GIT_SHORT_SHA={sha}");
+    // Re-run whenever HEAD or any ref changes (new commits, branch switches).
+    println!("cargo:rerun-if-changed=.git/HEAD");
+    println!("cargo:rerun-if-changed=.git/refs");
+}

nbd/src/main.rs

@@ -19,6 +19,12 @@ mod ticket;
 /// ```
 const CLAUDE_MD_SNIPPET: &str = include_str!("claude_md_snippet.md");
 
+/// Full version string embedded at compile time: `"X.Y.Z+shortsha"`.
+///
+/// The semver comes from `Cargo.toml` via `CARGO_PKG_VERSION`; the short SHA
+/// is injected by `build.rs` via `GIT_SHORT_SHA`.
+const VERSION: &str = concat!(env!("CARGO_PKG_VERSION"), "+", env!("GIT_SHORT_SHA"));
+
 #[cfg(test)]
 mod tests;
 
@@ -39,7 +45,7 @@ use crate::ticket::{generate_id, validate_priority, Status, Ticket, TicketType};
 /// ancestor directory that contains a `.nbd/` folder, discovered by traversing
 /// upward from the current working directory (like `git` finds `.git/`).
 #[derive(Parser)]
-#[command(name = "nbd", about = "Manage work tickets for agent workflows")]
+#[command(name = "nbd", about = "Manage work tickets for agent workflows", version = VERSION)]
 struct Cli {
     /// Output machine-readable JSON instead of a human-readable table.
     #[arg(long, global = true)]

nbd/tests/integration.rs

@@ -2158,3 +2158,33 @@ fn update_no_changes_prints_no_changes() {
         "should print '(no changes)' when nothing changed: {stdout}"
     );
 }
+
+// ── nbd --version tests ───────────────────────────────────────────────────────
+
+/// `nbd --version` exits 0 and stdout contains the semver and a git SHA.
+#[test]
+fn version_flag_exits_zero_with_semver() {
+    let tmp = tempfile::tempdir().expect("tempdir");
+    let output = std::process::Command::new(env!("CARGO_BIN_EXE_nbd"))
+        .arg("--version")
+        .current_dir(tmp.path())
+        .output()
+        .expect("failed to spawn nbd");
+
+    assert!(
+        output.status.success(),
+        "--version should exit 0, stderr: {}",
+        String::from_utf8_lossy(&output.stderr)
+    );
+    let stdout = String::from_utf8(output.stdout).unwrap();
+    // Should contain the package version (semver).
+    assert!(
+        stdout.contains("0.1.0"),
+        "--version should include semver: {stdout}"
+    );
+    // Should contain a '+' separator between semver and git SHA.
+    assert!(
+        stdout.contains('+'),
+        "--version should contain '+' separator: {stdout}"
+    );
+}