fix: show actual version when installed via go install

- Use runtime/debug.ReadBuildInfo() to read version from module info
- Falls back to ldflags version for GoReleaser builds
- Reads VCS commit hash and build time from build settings
- Removes outdated note from README about version showing as "dev"

Now when users run:
  go install github.com/itsdevcoffee/plum/cmd/plum@v0.3.4
  plum --version

They'll see:
  plum version v0.3.4
  commit: abc1234
  built: 2026-01-11T07:35:03Z

Instead of:
  plum version dev
  commit: none
  built: unknown

Author: itsdevcoffee

README.md

@@ -111,7 +111,6 @@ plum
 ```
 
 **Requirements:** Go 1.24+
-**Note:** Version will show as "dev" when installed this way. Use Homebrew or pre-built binaries for version tracking.
 
 **Troubleshooting:** If `plum` command isn't found after `go install`, add `$GOPATH/bin` to your PATH:
 ```bash

cmd/plum/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"os"
+	"runtime/debug"
 
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/itsdevcoffee/plum/internal/ui"
@@ -14,12 +15,47 @@ var (
 	date    = "unknown"
 )
 
+func getVersion() (ver, cmt, bDate string) {
+	// Try to get version from build info (works with go install)
+	if info, ok := debug.ReadBuildInfo(); ok && version == "dev" {
+		if info.Main.Version != "" && info.Main.Version != "(devel)" {
+			ver = info.Main.Version
+		} else {
+			ver = version
+		}
+
+		// Try to get commit from build settings
+		for _, setting := range info.Settings {
+			if setting.Key == "vcs.revision" && commit == "none" {
+				cmt = setting.Value[:7] // Short commit hash
+			}
+			if setting.Key == "vcs.time" && date == "unknown" {
+				bDate = setting.Value
+			}
+		}
+	}
+
+	// Use ldflags values if set (from GoReleaser)
+	if ver == "" {
+		ver = version
+	}
+	if cmt == "" {
+		cmt = commit
+	}
+	if bDate == "" {
+		bDate = date
+	}
+
+	return ver, cmt, bDate
+}
+
 func main() {
 	// Handle --version flag
 	if len(os.Args) > 1 && (os.Args[1] == "--version" || os.Args[1] == "-v") {
-		fmt.Printf("plum version %s\n", version)
-		fmt.Printf("  commit: %s\n", commit)
-		fmt.Printf("  built: %s\n", date)
+		ver, cmt, bDate := getVersion()
+		fmt.Printf("plum version %s\n", ver)
+		fmt.Printf("  commit: %s\n", cmt)
+		fmt.Printf("  built: %s\n", bDate)
 		os.Exit(0)
 	}