build: Add clap_complete, libc dependencies and git hash build script

Add clap_complete for shell completion generation and libc (unix-only)
for SIGPIPE handling. Create build.rs to embed the git commit hash at
compile time via cargo:rustc-env=GIT_HASH, enabling `lore version` to
display the short hash alongside the version number.

Co-Authored-By: Claude (us.anthropic.claude-opus-4-5-20251101-v1:0) <noreply@anthropic.com>

Cargo.lock

@@ -211,6 +211,15 @@ dependencies = [
  "strsim",
 ]
 
+[[package]]
+name = "clap_complete"
+version = "4.5.65"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "430b4dc2b5e3861848de79627b2bedc9f3342c7da5173a14eaa5d0f8dc18ae5d"
+dependencies = [
+ "clap",
+]
+
 [[package]]
 name = "clap_derive"
 version = "4.5.49"
@@ -1085,6 +1094,7 @@ dependencies = [
  "async-stream",
  "chrono",
  "clap",
+ "clap_complete",
  "comfy-table",
  "console",
  "dialoguer",
@@ -1092,6 +1102,7 @@ dependencies = [
  "flate2",
  "futures",
  "indicatif",
+ "libc",
  "open",
  "rand",
  "reqwest",

Cargo.toml

@@ -21,6 +21,7 @@ serde_json = "1"
 
 # CLI
 clap = { version = "4", features = ["derive", "env"] }
+clap_complete = "4"
 dialoguer = "0.12"
 console = "0.16"
 indicatif = "0.18"
@@ -46,6 +47,9 @@ flate2 = "1"
 chrono = { version = "0.4", features = ["serde"] }
 uuid = { version = "1", features = ["v4"] }
 
+[target.'cfg(unix)'.dependencies]
+libc = "0.2"
+
 # Logging
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }

build.rs

@@ -0,0 +1,10 @@
+fn main() {
+    let hash = std::process::Command::new("git")
+        .args(["rev-parse", "--short", "HEAD"])
+        .output()
+        .ok()
+        .and_then(|o| String::from_utf8(o.stdout).ok())
+        .unwrap_or_default();
+    println!("cargo:rustc-env=GIT_HASH={}", hash.trim());
+    println!("cargo:rerun-if-changed=.git/HEAD");
+}