refactor(zli): add typed ~/.zot config layer and strict validation (#4030)

feat(cli): add typed ~/.zot config layer and strict validation

Introduce pkg/cli/client/config.go with ZliConfigFile/ZliConfig and
ReadZliConfigFile, replacing the loose map[string]any load/save path in
config_cmd.go.

Parsing now rejects malformed JSON with ErrCliBadConfig and requires a
non-null configs array (ErrCliMissingConfigsField when wrapped). Each
profile must have non-empty _name and url.

Config commands delegate to typed helpers (Find, AddEntry, RemoveEntry,
GetVar/SetVar/ResetVar, FormatNames, WriteFile). Fresh or minimal files
still behave as empty via isFreshCliRead (ErrEmptyJSON or missing configs).

Tests: prefer t.Setenv("HOME", t.TempDir()) where CLI resolution uses --url
only; align CVE/client/search tests with mandatory profile URL and HOME
isolation.

Signed-off-by: Andrei Aaron <andreifdaaron@gmail.com>

errors/errors.go

@@ -49,6 +49,7 @@ func GetDetails(err error) map[string]string {
 var (
 	ErrBadConfig                        = errors.New("invalid server config")
 	ErrCliBadConfig                     = errors.New("invalid cli config")
+	ErrCliMissingConfigsField           = errors.New(`missing or null "configs" field`)
 	ErrRepoNotFound                     = errors.New("repository not found")
 	ErrRepoBadVersion                   = errors.New("unsupported repository layout version")
 	ErrRepoBadLayout                    = errors.New("invalid repository layout")