feat: Spring Boot config files in repos

application*.properties/.yml and bootstrap* files tracked by git are
listed under Repos, with their secret-looking keys as secrets.

- Keys whose name ends like a secret (password, secret, token, key, …)
  or whose value looks like one (Jasypt ENC(...), a URL or connection
  string with a password) are listed; providers.repos.spring.keys and
  .values replace the patterns, also in a repo's .lazysecrets.yaml.
- A file's details count the keys left out; ${VAR} values are marked
  as references, and a tracked file is only marked red when a listed
  value is in plain text.
- Later YAML/properties documents name their keys after the profile:
  spring.datasource.password (prod).
- Maven's @placeholders@ parse; Argo CD's applications.yaml and Helm
  templates aren't Spring files.
- A green leaf icon, themeable with springColor.

internal/config/config.go

@@ -15,6 +15,7 @@ import (
 	"go.yaml.in/yaml/v3"
 
 	"git.kebcloud.no/keb/lazysecrets/internal/commands"
+	"git.kebcloud.no/keb/lazysecrets/internal/provider/repo"
 	"git.kebcloud.no/keb/lazysecrets/internal/share"
 	"git.kebcloud.no/keb/lazysecrets/internal/update"
 )
@@ -153,6 +154,8 @@ type Repos struct {
 	// a repo's .sops.yaml creation_rules say where to look.
 	Include []string `yaml:"include"`
 	Exclude []string `yaml:"exclude"`
+	// Spring says which keys of Spring Boot config files are secrets.
+	Spring repo.SpringPatterns `yaml:"spring"`
 }
 
 type Azure struct {
@@ -292,6 +295,9 @@ func (c Config) validate(path string) error {
 			return fmt.Errorf("%s: %s: %s is negative", path, name, d)
 		}
 	}
+	if err := c.Providers.Repos.Spring.Check(); err != nil {
+		return fmt.Errorf("%s: providers.repos.%w", path, err)
+	}
 	for i, v := range c.Providers.Azure.Vaults {
 		if !strings.HasPrefix(v, "https://") {
 			return fmt.Errorf("%s: providers.azure.vaults[%d]: %q is not an https:// vault URL", path, i, v)