feat(v0.3): run git init and ensure .gitignore for project workspaces

After Create() returns, project mode now:
  1. Runs git init (or prints "git not found; skipped..." if git
     is unavailable)
  2. Calls EnsureGitignore, which is a no-op when a seed already
     supplied .gitignore (preserving the seed-wins rule end-to-end)

Both git unavailability and git init failure are non-fatal: ctask
warns and continues, so a missing/broken git toolchain never blocks
project creation.

cmd/new.go

@@ -2,6 +2,7 @@ package cmd
 
 import (
 	"fmt"
+	"os"
 
 	"github.com/spf13/cobra"
 	"github.com/warrenronsiek/ctask/internal/config"
@@ -97,6 +98,20 @@ func runNew(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
+	if newProject {
+		if !workspace.GitAvailable() {
+			fmt.Println("[ctask] git not found; skipped repository initialization")
+		} else {
+			if err := workspace.RunGitInit(ws.Path); err != nil {
+				fmt.Fprintf(os.Stderr, "[ctask] warning: %v\n", err)
+			}
+		}
+		// Seed-wins: EnsureGitignore is a no-op when a seed provided .gitignore.
+		if err := workspace.EnsureGitignore(ws.Path); err != nil {
+			fmt.Fprintf(os.Stderr, "[ctask] warning: failed to create .gitignore: %v\n", err)
+		}
+	}
+
 	relPath := workspace.RelativePath(root, ws.Path)
 	fmt.Printf("[ctask] created %s\n", relPath)