merge: combine zoxide and Atuin context navigation

# Conflicts:
#	README.md
#	internal/config/config.go
#	internal/config/config_test.go
#	root/config_cmd.go
#	root/config_cmd_test.go
#	root/init.go

internal/config/config.go

@@ -83,6 +83,11 @@ type ZoxideConfig struct {
 	ExtendCd bool `toml:"extend-cd"`
 }
 
+type HistoryConfig struct {
+	// Scope controls Atuin filtering for non-empty history searches.
+	Scope string `toml:"scope"`
+}
+
 type SuggestOnEmptyConfig struct {
 	Enabled       bool `toml:"enabled"`
 	DebounceMS    int  `toml:"debounce_ms"`
@@ -130,6 +135,7 @@ type Config struct {
 	Core        CoreConfig        `toml:"core"`
 	UI          UIConfig          `toml:"ui"`
 	Git         GitConfig         `toml:"git"`
+	History     HistoryConfig     `toml:"history"`
 	Updater     UpdaterConfig     `toml:"updater"`
 	AI          AIConfig          `toml:"ai"`
 	Zoxide      ZoxideConfig      `toml:"zoxide"`
@@ -288,6 +294,11 @@ func validate(cfg *Config) error {
 		return fmt.Errorf("core.shell: invalid value %q (want: bash|zsh|fish)", cfg.Core.Shell)
 	}
 
+	validHistoryScopes := map[string]bool{"global": true, "directory": true, "workspace": true, "hybrid": true}
+	if !validHistoryScopes[cfg.History.Scope] {
+		return fmt.Errorf("history.scope: invalid value %q (want: global|directory|workspace|hybrid)", cfg.History.Scope)
+	}
+
 	validChannels := map[string]bool{"stable": true, "nightly": true}
 	if !validChannels[cfg.Updater.Channel] {
 		return fmt.Errorf("updater.channel: invalid value %q (want: stable|nightly)", cfg.Updater.Channel)

internal/config/config_test.go

@@ -33,6 +33,9 @@ func TestDefaultConfigAndState(t *testing.T) {
 	if cfg.Zoxide.ExtendCd {
 		t.Errorf("expected zoxide cd extension to be disabled by default")
 	}
+	if cfg.History.Scope != "global" {
+		t.Errorf("expected global history scope, got %q", cfg.History.Scope)
+	}
 
 	// test manual provider registration
 	cfg.AI.Provider = "custom"
@@ -210,6 +213,21 @@ func TestValidateAutoUpdateRange(t *testing.T) {
 	}
 }
 
+func TestValidateHistoryScope(t *testing.T) {
+	cfg := DefaultConfig()
+	for _, scope := range []string{"global", "directory", "workspace", "hybrid"} {
+		cfg.History.Scope = scope
+		if err := validate(cfg); err != nil {
+			t.Errorf("expected history scope %q to be valid: %v", scope, err)
+		}
+	}
+
+	cfg.History.Scope = "session"
+	if err := validate(cfg); err == nil {
+		t.Error("expected unsupported history scope to be rejected")
+	}
+}
+
 func TestLoadSave(t *testing.T) {
 	tmpDir, err := os.MkdirTemp("", "iris-config-test")
 	if err != nil {

internal/config/defaults.go

@@ -29,6 +29,9 @@ func DefaultConfig() *Config {
 			FilterActiveBranch:  true,
 			DeduplicateBranches: true,
 		},
+		History: HistoryConfig{
+			Scope: "global",
+		},
 		Updater: UpdaterConfig{
 			CheckOnStartup: true,
 			Channel:        "stable",

internal/workspace/workspace.go

@@ -108,6 +108,21 @@ func detectGitInfo(cwd string) (hasGit bool, branch string) {
 	return hasGit, ""
 }
 
+// GitRoot returns the repository root containing cwd, or an empty string.
+func GitRoot(cwd string) string {
+	dir := filepath.Clean(cwd)
+	for {
+		if _, err := os.Stat(filepath.Join(dir, ".git")); err == nil {
+			return dir
+		}
+		parent := filepath.Dir(dir)
+		if parent == dir {
+			return ""
+		}
+		dir = parent
+	}
+}
+
 type cacheEntry struct {
 	key  string // cwd + "|" + dirModTime
 	info WorkspaceInfo

internal/workspace/workspace_test.go

@@ -44,6 +44,24 @@ func TestDetect_EmptyDirectory(t *testing.T) {
 	}
 }
 
+func TestGitRoot(t *testing.T) {
+	repo := t.TempDir()
+	nested := filepath.Join(repo, "internal", "pkg")
+	if err := os.MkdirAll(filepath.Join(repo, ".git"), 0755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.MkdirAll(nested, 0755); err != nil {
+		t.Fatal(err)
+	}
+
+	if got := GitRoot(nested); got != repo {
+		t.Fatalf("expected git root %q, got %q", repo, got)
+	}
+	if got := GitRoot(t.TempDir()); got != "" {
+		t.Fatalf("expected no git root, got %q", got)
+	}
+}
+
 func TestDetect_NodeProject(t *testing.T) {
 	tmp := t.TempDir()
 	_ = os.WriteFile(filepath.Join(tmp, "package.json"), []byte("{}"), 0644)
@@ -135,7 +153,7 @@ func TestDetectCached_BranchSwitchWithoutDirChange(t *testing.T) {
 	// Simulate branch switch by updating .git/HEAD only
 	// (this does not update the modtime of tmp on typical filesystems since tmp's direct children didn't change)
 	_ = os.WriteFile(headPath, []byte("ref: refs/heads/feature\n"), 0644)
-	
+
 	// Force the modtime of HEAD to be distinct to avoid flakiness on low-res file systems
 	infoAfter, _ := os.Stat(headPath)
 	newMod := infoAfter.ModTime().Add(2 * time.Second)