feat(services): traefik routing overrides via allowlisted middleware labels (#64)

services.traefik_labels (jsonb) holds operator-defined Traefik
middlewares keyed 'middlewares.<name>.<type>[.<field>]', validated
against an allowlist at write time. edgeLabels (extracted from
createReplica) scopes each definition to the service router as
<router>-<name> and auto-attaches it to the router's middleware chain
after builtins. Router/service/provider-level keys are rejected.

Surfaces: create/update API fields, services create/update
--traefik-label (repeatable, key=value), MCP arg docs, OpenAPI +
regenerated types, service-page Access editor (Routing overrides
card + textarea).

Also marks three stale ROADMAP2 items shipped: notification producers
round-out, build-on-node (PR #60), mobile env/domains/scaling (PR #61).

Generated with [Devin](https://devin.ai)

Co-authored-by: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

app/backend/internal/api/services_routing_test.go

@@ -0,0 +1,64 @@
+package api
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestNormalizeTraefikLabels(t *testing.T) {
+	valid := map[string]string{
+		"middlewares.rl.ratelimit.average":                             "100",
+		"middlewares.rl.ratelimit.period":                              "1m",
+		"middlewares.sec.headers.customrequestheaders.X-Frame-Options": "DENY",
+		"middlewares.gzip.compress":                                    "true",
+	}
+	out, err := normalizeTraefikLabels(valid)
+	if err != nil {
+		t.Fatalf("valid labels rejected: %v", err)
+	}
+	if len(out) != len(valid) {
+		t.Fatalf("expected %d labels, got %d", len(valid), len(out))
+	}
+	if out["middlewares.gzip.compress"] != "true" {
+		t.Fatalf("flag-style middleware missing: %v", out)
+	}
+}
+
+func TestNormalizeTraefikLabelsLowercasesType(t *testing.T) {
+	out, err := normalizeTraefikLabels(map[string]string{
+		"middlewares.rl.RateLimit.average": "10",
+	})
+	if err != nil {
+		t.Fatalf("mixed-case type rejected: %v", err)
+	}
+	if out["middlewares.rl.ratelimit.average"] != "10" {
+		t.Fatalf("type not lowercased: %v", out)
+	}
+}
+
+func TestNormalizeTraefikLabelsRejects(t *testing.T) {
+	cases := map[string]string{
+		"traefik.enable":                                 "true", // provider-level
+		"middlewares..ratelimit.average":                 "1",    // empty name
+		"middlewares.x.evilinject.thing":                 "1",    // unknown type
+		"routers.svc.rule":                               "x",    // router hijack
+		"middlewares.x.ratelimit.average.bad\ninjection": "1",    // control char in key fails regex
+	}
+	for k, v := range cases {
+		if _, err := normalizeTraefikLabels(map[string]string{k: v}); err == nil {
+			t.Fatalf("key %q should have been rejected", k)
+		}
+	}
+}
+
+func TestNormalizeTraefikLabelsRejectsBadValues(t *testing.T) {
+	if _, err := normalizeTraefikLabels(map[string]string{"middlewares.a.ratelimit.average": ""}); err == nil {
+		t.Fatal("empty value accepted")
+	}
+	if _, err := normalizeTraefikLabels(map[string]string{"middlewares.a.ratelimit.average": strings.Repeat("x", 600)}); err == nil {
+		t.Fatal("oversized value accepted")
+	}
+	if _, err := normalizeTraefikLabels(map[string]string{"middlewares.a.ratelimit.average": "1\nmalicious"}); err == nil {
+		t.Fatal("newline value accepted")
+	}
+}