Add comprehensive build identification to agent

- Add git hash (short and full), branch, commit date
- Add build timestamp and dirty/clean state
- Add build profile (debug/release) and target triple
- New `version-info` command shows all build details
- `--version` now shows version-hash format (e.g., 0.1.0-4614df04)
- Startup logs now include version hash and build info

Example output:
  GuruConnect v0.1.0
  Git:     4614df04 (clean)
  Branch:  main
  Commit:  2025-12-30 06:30:28 -0700
  Built:   2025-12-30 15:25:20 UTC
  Profile: release
  Target:  x86_64-pc-windows-msvc

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

agent/Cargo.toml

@@ -99,6 +99,7 @@ windows-service = "0.7"
 [build-dependencies]
 prost-build = "0.13"
 winres = "0.1"
+chrono = "0.4"
 
 [[bin]]
 name = "guruconnect"

agent/build.rs

@@ -1,4 +1,5 @@
 use std::io::Result;
+use std::process::Command;
 
 fn main() -> Result<()> {
     // Compile protobuf definitions
@@ -7,6 +8,71 @@ fn main() -> Result<()> {
     // Rerun if proto changes
     println!("cargo:rerun-if-changed=../proto/guruconnect.proto");
 
+    // Rerun if git HEAD changes (new commits)
+    println!("cargo:rerun-if-changed=../.git/HEAD");
+    println!("cargo:rerun-if-changed=../.git/index");
+
+    // Build timestamp (UTC)
+    let build_timestamp = chrono::Utc::now().format("%Y-%m-%d %H:%M:%S UTC").to_string();
+    println!("cargo:rustc-env=BUILD_TIMESTAMP={}", build_timestamp);
+
+    // Git commit hash (short)
+    let git_hash = Command::new("git")
+        .args(["rev-parse", "--short=8", "HEAD"])
+        .output()
+        .ok()
+        .and_then(|o| String::from_utf8(o.stdout).ok())
+        .map(|s| s.trim().to_string())
+        .unwrap_or_else(|| "unknown".to_string());
+    println!("cargo:rustc-env=GIT_HASH={}", git_hash);
+
+    // Git commit hash (full)
+    let git_hash_full = Command::new("git")
+        .args(["rev-parse", "HEAD"])
+        .output()
+        .ok()
+        .and_then(|o| String::from_utf8(o.stdout).ok())
+        .map(|s| s.trim().to_string())
+        .unwrap_or_else(|| "unknown".to_string());
+    println!("cargo:rustc-env=GIT_HASH_FULL={}", git_hash_full);
+
+    // Git branch name
+    let git_branch = Command::new("git")
+        .args(["rev-parse", "--abbrev-ref", "HEAD"])
+        .output()
+        .ok()
+        .and_then(|o| String::from_utf8(o.stdout).ok())
+        .map(|s| s.trim().to_string())
+        .unwrap_or_else(|| "unknown".to_string());
+    println!("cargo:rustc-env=GIT_BRANCH={}", git_branch);
+
+    // Git dirty state (uncommitted changes)
+    let git_dirty = Command::new("git")
+        .args(["status", "--porcelain"])
+        .output()
+        .ok()
+        .map(|o| !o.stdout.is_empty())
+        .unwrap_or(false);
+    println!("cargo:rustc-env=GIT_DIRTY={}", if git_dirty { "dirty" } else { "clean" });
+
+    // Git commit date
+    let git_commit_date = Command::new("git")
+        .args(["log", "-1", "--format=%ci"])
+        .output()
+        .ok()
+        .and_then(|o| String::from_utf8(o.stdout).ok())
+        .map(|s| s.trim().to_string())
+        .unwrap_or_else(|| "unknown".to_string());
+    println!("cargo:rustc-env=GIT_COMMIT_DATE={}", git_commit_date);
+
+    // Build profile (debug/release)
+    let profile = std::env::var("PROFILE").unwrap_or_else(|_| "unknown".to_string());
+    println!("cargo:rustc-env=BUILD_PROFILE={}", profile);
+
+    // Target triple
+    let target = std::env::var("TARGET").unwrap_or_else(|_| "unknown".to_string());
+    println!("cargo:rustc-env=BUILD_TARGET={}", target);
+
     // On Windows, embed the manifest for UAC elevation
     #[cfg(target_os = "windows")]
     {

agent/src/main.rs

@@ -29,6 +29,66 @@ pub mod proto {
     include!(concat!(env!("OUT_DIR"), "/guruconnect.rs"));
 }
 
+/// Build information embedded at compile time
+pub mod build_info {
+    /// Cargo package version (from Cargo.toml)
+    pub const VERSION: &str = env!("CARGO_PKG_VERSION");
+
+    /// Git commit hash (short, 8 chars)
+    pub const GIT_HASH: &str = env!("GIT_HASH");
+
+    /// Git commit hash (full)
+    pub const GIT_HASH_FULL: &str = env!("GIT_HASH_FULL");
+
+    /// Git branch name
+    pub const GIT_BRANCH: &str = env!("GIT_BRANCH");
+
+    /// Git dirty state ("clean" or "dirty")
+    pub const GIT_DIRTY: &str = env!("GIT_DIRTY");
+
+    /// Git commit date
+    pub const GIT_COMMIT_DATE: &str = env!("GIT_COMMIT_DATE");
+
+    /// Build timestamp (UTC)
+    pub const BUILD_TIMESTAMP: &str = env!("BUILD_TIMESTAMP");
+
+    /// Build profile (debug/release)
+    pub const BUILD_PROFILE: &str = env!("BUILD_PROFILE");
+
+    /// Target triple (e.g., x86_64-pc-windows-msvc)
+    pub const BUILD_TARGET: &str = env!("BUILD_TARGET");
+
+    /// Short version string for display (version + git hash)
+    pub fn short_version() -> String {
+        if GIT_DIRTY == "dirty" {
+            format!("{}-{}-dirty", VERSION, GIT_HASH)
+        } else {
+            format!("{}-{}", VERSION, GIT_HASH)
+        }
+    }
+
+    /// Full version string with all details
+    pub fn full_version() -> String {
+        format!(
+            "GuruConnect v{}\n\
+             Git:     {} ({})\n\
+             Branch:  {}\n\
+             Commit:  {}\n\
+             Built:   {}\n\
+             Profile: {}\n\
+             Target:  {}",
+            VERSION,
+            GIT_HASH,
+            GIT_DIRTY,
+            GIT_BRANCH,
+            GIT_COMMIT_DATE,
+            BUILD_TIMESTAMP,
+            BUILD_PROFILE,
+            BUILD_TARGET
+        )
+    }
+}
+
 use anyhow::Result;
 use clap::{Parser, Subcommand};
 use tracing::{info, error, warn, Level};
@@ -46,7 +106,7 @@ use windows::Win32::UI::WindowsAndMessaging::{ShowWindow, SW_SHOW};
 /// GuruConnect Remote Desktop
 #[derive(Parser)]
 #[command(name = "guruconnect")]
-#[command(version, about = "Remote desktop agent and viewer")]
+#[command(version = concat!(env!("CARGO_PKG_VERSION"), "-", env!("GIT_HASH")), about = "Remote desktop agent and viewer")]
 struct Cli {
     #[command(subcommand)]
     command: Option<Commands>,
@@ -102,6 +162,10 @@ enum Commands {
         /// The guruconnect:// URL to handle
         url: String,
     },
+
+    /// Show detailed version and build information
+    #[command(name = "version-info")]
+    VersionInfo,
 }
 
 fn main() -> Result<()> {
@@ -115,7 +179,8 @@ fn main() -> Result<()> {
         .with_thread_ids(true)
         .init();
 
-    info!("GuruConnect v{}", env!("CARGO_PKG_VERSION"));
+    info!("GuruConnect {} ({})", build_info::short_version(), build_info::BUILD_TARGET);
+    info!("Built: {} | Commit: {}", build_info::BUILD_TIMESTAMP, build_info::GIT_COMMIT_DATE);
 
     match cli.command {
         Some(Commands::Agent { code }) => {
@@ -133,6 +198,13 @@ fn main() -> Result<()> {
         Some(Commands::Launch { url }) => {
             run_launch(&url)
         }
+        Some(Commands::VersionInfo) => {
+            // Show detailed version info (allocate console on Windows for visibility)
+            #[cfg(windows)]
+            show_debug_console();
+            println!("{}", build_info::full_version());
+            Ok(())
+        }
         None => {
             // Legacy mode: if a support code was provided, run as agent
             if let Some(code) = cli.support_code {