feat(zddc-server): no-slash canonical folders → default tool, even

when missing on disk

Mirror of the existing IsDir-branch behavior at line 873
(<project>/working → mdedit, <project>/staging → transmittal,
<project>/archive → archive) for the case where the folder doesn't
exist on disk yet. Without this, GET <project>/working on a fresh
project 404s instead of opening mdedit rooted at the (virtual)
working directory.

Behavior matrix for canonical project-root folders that don't yet
exist on disk:

  GET <project>/archive    → archive tool (project-root mode)
  GET <project>/archive/   → empty browse listing
  GET <project>/working    → mdedit rooted at working/
  GET <project>/working/   → empty browse listing (with synthetic
                             <viewer-email>/ home entry)
  GET <project>/staging    → transmittal rooted at staging/
  GET <project>/staging/   → empty browse listing
  GET <project>/reviewing  → 301 to /reviewing/ (no default app)
  GET <project>/reviewing/ → empty browse listing
  GET <project>/random     → 404 (still — non-canonical)
  GET <project>/random/    → 404 (still — non-canonical)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

zddc/cmd/zddc-server/main.go

@@ -841,18 +841,38 @@ func dispatch(cfg config.Config, idx *archive.Index, ring *handler.LogRing, apps
 					}
 				}
 			}
-			// Empty-listing fallback for canonical project-root folders.
+			// Canonical project-root folder fallback. <project>/{archive,
-			// <project>/{archive,working,staging,reviewing}/ that don't
+			// working,staging,reviewing}[/] should land on a usable view
-			// yet exist on disk should render as a usable empty
+			// (default tool or empty listing) rather than 404, so the
-			// directory view rather than 404, so the stage-strip nav
+			// stage-strip nav works on a fresh project that hasn't yet
-			// links land on a real page on a fresh project. The
+			// been written to. Two shapes:
-			// matching read-side fallback in fs.ListDirectory returns
+			//
-			// 200 + [] for the same paths; we fall through to
+			//   <project>/working   → mdedit rooted at working/
-			// ServeDirectory which goes through that path and applies
+			//                         (matches the existing IsDir branch
-			// ACL via the parent project's .zddc cascade.
+			//                          for an existing folder)
+			//   <project>/working/  → ServeDirectory → fs.ListDirectory
+			//                         returns 200 + [] for the empty case
+			//
+			// reviewing/ has no default app, so the no-slash form 301s
+			// to the slash form.
 			if (r.Method == http.MethodGet || r.Method == http.MethodHead) &&
-				strings.HasSuffix(urlPath, "/") &&
+				zddc.IsProjectRootFolder(strings.Trim(strings.TrimPrefix(urlPath, "/"), "/")) {
-				zddc.IsProjectRootFolder(strings.TrimPrefix(strings.TrimSuffix(urlPath, "/"), "/")) {
+				if !strings.HasSuffix(urlPath, "/") {
+					if app := apps.DefaultAppAt(cfg.Root, absPath); app != "" && appsSrv != nil {
+						if apps.AppAvailableAt(cfg.Root, absPath, app) {
+							chain, _ := zddc.EffectivePolicy(cfg.Root, absPath)
+							if allowed, _ := policy.AllowFromChain(r.Context(), handler.DeciderFromContext(r), chain, email, urlPath); !allowed {
+								http.Error(w, "Forbidden", http.StatusForbidden)
+								return
+							}
+							appsSrv.Serve(w, r, app, chain, absPath)
+							return
+						}
+					}
+					// No default app (reviewing/) — redirect to slash form.
+					http.Redirect(w, r, urlPath+"/", http.StatusMovedPermanently)
+					return
+				}
 				handler.ServeDirectory(cfg, w, r)
 				return
 			}

zddc/cmd/zddc-server/main_test.go

@@ -517,6 +517,47 @@ func TestDispatchEmptyCanonicalProjectFolders(t *testing.T) {
 		})
 	}
 
+	// No-trailing-slash form on a canonical folder → default app
+	// (mdedit for working/, transmittal for staging/, archive for
+	// archive/). Mirror of the existing "no-slash → default app"
+	// behavior at the IsDir branch, extended to cover the case where
+	// the folder doesn't exist on disk yet.
+	noSlashDefaultApp := []struct {
+		stage  string
+		expect string // substring that should appear in the response body
+	}{
+		{"working", "ZDDC Markdown"},
+		{"staging", "ZDDC Transmittal"},
+		{"archive", "ZDDC Archive"},
+	}
+	for _, tc := range noSlashDefaultApp {
+		t.Run("no-slash/"+tc.stage+" → default app", func(t *testing.T) {
+			req := httptest.NewRequest(http.MethodGet, "/Project/"+tc.stage, nil)
+			rec := httptest.NewRecorder()
+			dispatch(cfg, idx, ring, appsSrv, nil, rec, req)
+			if rec.Code != http.StatusOK {
+				t.Fatalf("status=%d, want 200; body=%s", rec.Code, rec.Body.String())
+			}
+			if !strings.Contains(rec.Body.String(), tc.expect) {
+				t.Errorf("%s/ body missing %q", tc.stage, tc.expect)
+			}
+		})
+	}
+
+	// reviewing/ has no default tool — no-slash form should 301 to
+	// the slash form (which then renders the empty listing).
+	t.Run("no-slash/reviewing → 301 to slash", func(t *testing.T) {
+		req := httptest.NewRequest(http.MethodGet, "/Project/reviewing", nil)
+		rec := httptest.NewRecorder()
+		dispatch(cfg, idx, ring, appsSrv, nil, rec, req)
+		if rec.Code != http.StatusMovedPermanently {
+			t.Errorf("status=%d, want 301", rec.Code)
+		}
+		if loc := rec.Header().Get("Location"); loc != "/Project/reviewing/" {
+			t.Errorf("Location=%q, want %q", loc, "/Project/reviewing/")
+		}
+	})
+
 	// Non-canonical missing folder still 404s (the fallback is
 	// scoped to the four canonical names, not a blanket "missing →
 	// empty" rule).