test(coverage): add targeted tests to raise per-package coverage gates

- internal/homesick/version: new version_test.go covers String constant
  and semver format validation
- internal/homesick/cli: add list, generate, clone, status, diff, and
  git-repo helper tests; coverage raised from 62.5% to 71.2%
- internal/homesick/core: new helpers_test.go covers runGit pretend,
  actionVerb, sayStatus, unlinkPath, linkPath, readSubdirs,
  matchesIgnoredDir, confirmDestroy, ExecAll edge cases, and
  Link/Unlink default castle wrappers; core_test.go and pull_test.go
  extended with New constructor and PullAll quiet-mode tests;
  exec_test.go extended with ExecAll no-repos-dir and error-wrap tests;
  coverage raised from 75.6% to 80.2%

internal/homesick/cli/cli_test.go

@@ -5,9 +5,13 @@ import (
 	"os"
 	"path/filepath"
 	"testing"
+	"time"
 
 	"git.hrafn.xyz/aether/gosick/internal/homesick/cli"
 	"git.hrafn.xyz/aether/gosick/internal/homesick/version"
+	git "github.com/go-git/go-git/v5"
+	"github.com/go-git/go-git/v5/config"
+	"github.com/go-git/go-git/v5/plumbing/object"
 	"github.com/stretchr/testify/require"
 	"github.com/stretchr/testify/suite"
 )
@@ -32,6 +36,32 @@ func (s *CLISuite) SetupTest() {
 	s.stderr = &bytes.Buffer{}
 }
 
+func (s *CLISuite) createCastleRepo(castle string) string {
+	castleRoot := filepath.Join(s.homeDir, ".homesick", "repos", castle)
+	repo, err := git.PlainInit(castleRoot, false)
+	require.NoError(s.T(), err)
+
+	filePath := filepath.Join(castleRoot, "home", ".vimrc")
+	require.NoError(s.T(), os.MkdirAll(filepath.Dir(filePath), 0o755))
+	require.NoError(s.T(), os.WriteFile(filePath, []byte("set number\n"), 0o644))
+
+	wt, err := repo.Worktree()
+	require.NoError(s.T(), err)
+	_, err = wt.Add("home/.vimrc")
+	require.NoError(s.T(), err)
+	_, err = wt.Commit("initial", &git.CommitOptions{Author: &object.Signature{
+		Name:  "Behavior Test",
+		Email: "behavior@test.local",
+		When:  time.Now(),
+	}})
+	require.NoError(s.T(), err)
+
+	_, err = repo.CreateRemote(&config.RemoteConfig{Name: "origin", URLs: []string{"git://example.com/test.git"}})
+	require.NoError(s.T(), err)
+
+	return castleRoot
+}
+
 func (s *CLISuite) TestRun_VersionAliases() {
 	for _, args := range [][]string{{"-v"}, {"--version"}, {"version"}} {
 		s.stdout.Reset()
@@ -191,3 +221,52 @@ func (s *CLISuite) TestRun_Commit_PositionalMessageCompatibility() {
 	require.Contains(s.T(), s.stdout.String(), "git commit -m behavior-suite-commit")
 	require.Empty(s.T(), s.stderr.String())
 }
+
+func (s *CLISuite) TestRun_List_NoArguments() {
+	s.createCastleRepo("dotfiles")
+
+	exitCode := cli.Run([]string{"list"}, s.stdout, s.stderr)
+
+	require.Equal(s.T(), 0, exitCode)
+	require.Contains(s.T(), s.stdout.String(), "dotfiles")
+	require.Empty(s.T(), s.stderr.String())
+}
+
+func (s *CLISuite) TestRun_Generate_CreatesNewCastle() {
+	castlePath := filepath.Join(s.T().TempDir(), "my-castle")
+
+	exitCode := cli.Run([]string{"generate", castlePath}, s.stdout, s.stderr)
+
+	require.Equal(s.T(), 0, exitCode)
+	require.DirExists(s.T(), filepath.Join(castlePath, ".git"))
+	require.DirExists(s.T(), filepath.Join(castlePath, "home"))
+}
+
+func (s *CLISuite) TestRun_Clone_WithoutArgs() {
+	exitCode := cli.Run([]string{"clone"}, s.stdout, s.stderr)
+
+	// Clone requires arguments, should fail
+	require.NotEqual(s.T(), 0, exitCode)
+}
+
+func (s *CLISuite) TestRun_Status_DefaultCastle() {
+	castleRoot := s.createCastleRepo("dotfiles")
+	require.NoError(s.T(), os.WriteFile(filepath.Join(castleRoot, "home", ".vimrc"), []byte("changed\n"), 0o644))
+
+	exitCode := cli.Run([]string{"status"}, s.stdout, s.stderr)
+
+	require.Equal(s.T(), 0, exitCode)
+	require.Contains(s.T(), s.stdout.String(), "modified:")
+	require.Empty(s.T(), s.stderr.String())
+}
+
+func (s *CLISuite) TestRun_Diff_DefaultCastle() {
+	castleRoot := s.createCastleRepo("dotfiles")
+	require.NoError(s.T(), os.WriteFile(filepath.Join(castleRoot, "home", ".vimrc"), []byte("changed\n"), 0o644))
+
+	exitCode := cli.Run([]string{"diff"}, s.stdout, s.stderr)
+
+	require.Equal(s.T(), 0, exitCode)
+	require.Contains(s.T(), s.stdout.String(), "diff --git")
+	require.Empty(s.T(), s.stderr.String())
+}