Normalize the default configuration discovery paths for all three config files, and update documentation and tests accordingly

internal/app/session_cli_test.go

@@ -4,14 +4,15 @@ import (
 	"bytes"
 	"context"
 	"os"
-	"path/filepath"
 	"strings"
 	"testing"
+
+	"gitea.maximumdirect.net/eric/narratio/internal/config"
 )
 
 func TestPlanUsesDiscoveredSessionTemplateWithSessionIDs(t *testing.T) {
 	workspaceRoot := t.TempDir()
-	pipelinePath, _, sessionPath := writeValidConfigFiles(t, workspaceRoot)
+	pipelinePath, campaignPath, sessionPath := writeValidConfigFiles(t, workspaceRoot)
 
 	sessionTemplate := `session_id: "{{ session_id }}"
 previous_session_id: "{{ previous_session_id }}"
@@ -26,19 +27,14 @@ inputs:
 		t.Fatalf("write session template: %v", err)
 	}
 
-	cwd := filepath.Dir(sessionPath)
-	originalWD, err := os.Getwd()
-	if err != nil {
-		t.Fatalf("Getwd(): %v", err)
-	}
-	if err := os.Chdir(cwd); err != nil {
-		t.Fatalf("Chdir(%q): %v", cwd, err)
-	}
-	t.Cleanup(func() { _ = os.Chdir(originalWD) })
+	origSessionDefaults := append([]string(nil), config.DefaultSessionConfigSearchPaths...)
+	config.DefaultSessionConfigSearchPaths = []string{sessionPath}
+	t.Cleanup(func() { config.DefaultSessionConfigSearchPaths = origSessionDefaults })
 
 	var out bytes.Buffer
 	if err := Plan(context.Background(), []string{
 		"--config", pipelinePath,
+		"--campaign", campaignPath,
 		"--session-id", "2026-04-04",
 		"--previous-session-id", "2026-03-28",
 	}, &out); err != nil {
@@ -111,7 +107,7 @@ func TestRunStageAcceptsSessionIDFlagAndParsesStageName(t *testing.T) {
 }
 
 func TestResolveSessionConfigPathErrorIncludesSearchedPaths(t *testing.T) {
-	_, err := resolveSessionConfigPathWithCandidates("", []string{"./session.yml", "/usr/local/etc/narratio/session.yml", "/etc/narratio/session.yml"})
+	_, err := resolveSessionConfigPathWithCandidates("", []string{"/usr/local/etc/narratio/session.yml", "/etc/narratio/session.yml"})
 	if err == nil {
 		t.Fatal("expected error, got nil")
 	}