feat(apps): stepped creation wizard, branch previews, and app-creation fixes

This session (frontend focus):
- Rebuild /apps/new as a 4-step wizard (Basics → Configure → Trigger → Review):
  WizardRail, SourceKindPicker card grid, AppManifest review, per-step validation,
  ConfirmDialog-based unsaved-changes guard.
- Extract lib/workload/sourceForms.ts (single source of truth for source_config)
  + {Image,Compose,Static,Dockerfile}SourceForm + StaticDiscoveryWizard; fold the
  /apps/[id] edit form onto the same components (removes the duplication). Add
  vitest + sourceForms unit tests.
- Branch preview environments UI: /chain is_preview/preview_branch + a Preview
  environments panel on /apps/[id] (per-branch URLs, ConfirmDialog teardown, armed
  state); RegistryImagePicker on the registry trigger and the image source.
- Fixes: image-inspect 404 -> admin-gated POST /api/discovery/image/inspect;
  conflict-panel blur flicker; friendly localized discovery errors; CPU/Memory
  label hints; dashboard + /apps "Total workloads" count only source_kind workloads
  (drop stale trigger_kind gate); NPM cert/access-list name cache; EntityPicker
  empty-list guard.
- Update CLAUDE.md frontend conventions + add a Build & Test section.

Also captures pre-existing in-progress platform work (not from this session):
workload notifications, Prometheus metrics export, store lockfile, health probes,
backup hardening, and related store/webhook/scheduler changes.

internal/workload/plugin/source/dockerfile/env.go

@@ -0,0 +1,37 @@
+package dockerfile
+
+import (
+	"log/slog"
+
+	"github.com/alexei/tinyforge/internal/crypto"
+	"github.com/alexei/tinyforge/internal/workload/plugin"
+)
+
+// buildEnv flattens workload_env rows into the KEY=VALUE list Docker
+// expects. Mirrors the static plugin's env helper exactly so the two
+// plugins handle decrypt failures the same way: log + skip the one
+// entry rather than fail the deploy. Bricking a build because one
+// rotated key missed an env entry would be worse than running with
+// the variable unset and a single warning in the operator's log.
+func buildEnv(deps plugin.Deps, workloadID string) []string {
+	rows, err := deps.Store.ListWorkloadEnv(workloadID)
+	if err != nil {
+		slog.Warn("dockerfile source: list workload env", "workload", workloadID, "error", err)
+		return nil
+	}
+	out := make([]string, 0, len(rows))
+	for _, e := range rows {
+		value := e.Value
+		if e.Encrypted {
+			decrypted, err := crypto.Decrypt(deps.EncKey, e.Value)
+			if err != nil {
+				slog.Warn("dockerfile source: decrypt env value",
+					"workload", workloadID, "key", e.Key, "error", err)
+				continue
+			}
+			value = decrypted
+		}
+		out = append(out, e.Key+"="+value)
+	}
+	return out
+}