feat: Docker Compose files in repos

compose.yaml, docker-compose.yml and their variants tracked by git are
listed under Repos, their services' environment variables as secrets,
named service.VAR.

- environment as a map or a list, and <<: *anchors shared between
  services; the secret patterns pick the keys, the rest hidden, with
  compose.secretPatterns for compose files' own.
- ${VAR}, $VAR, ${VAR:?…} and variables without a value are marked as
  references; docker-compose.example.yml and the like are hidden.
- Jasypt values decrypt with the service's JASYPT_ENCRYPTOR_PASSWORD.
- A blue Docker icon, themeable with composeColor.

internal/provider/repo/details.go

@@ -25,10 +25,10 @@ func (p *Provider) Details(ctx context.Context, c provider.Container) ([]provide
 	var out []provider.Attr
 	meta, isSops := readMeta(c.ID)
 	// A plain file's values are at risk in git, unless they're all Jasypt;
-	// a Spring file's only when one of its secrets is in plain text.
+	// a config file's only when one of its secrets is in plain text.
 	plain := !isSops
-	if !isSops && IsSpring(c.ID) {
-		out, plain = p.springDetails(c)
+	if t, ok := configTypeOf(c.ID); ok && !isSops {
+		out, plain = p.configDetails(t, c)
 	} else if isSops {
 		out = append(out, provider.Attr{Label: "encryption", Value: "sops · " + strings.Join(meta.methods, ", ")})
 		for i, k := range meta.recipients {