Fix F-08, F-13: Adjust lockout expiration logic and enforce password length in tests

- Corrected lockout logic (`IsLockedOut`) to properly evaluate failed login thresholds within the rolling window, ensuring stale attempts outside the window do not trigger lockout.
- Updated test passwords in `grpcserver_test.go` to comply with 12-character minimum requirement.
- Reformatted import blocks with `goimports` to address lint warnings.
- Verified all tests pass and linter is clean.

internal/grpcserver/grpcserver_test.go

@@ -498,7 +498,7 @@ func TestUpdateAccount(t *testing.T) {
 
 	createResp, err := cl.CreateAccount(authCtx(adminTok), &mciasv1.CreateAccountRequest{
 		Username:    "updateme",
-		Password:    "pass12345",
+		Password:    "pass123456789",
 		AccountType: "human",
 	})
 	if err != nil {
@@ -532,7 +532,7 @@ func TestSetAndGetRoles(t *testing.T) {
 
 	createResp, err := cl.CreateAccount(authCtx(adminTok), &mciasv1.CreateAccountRequest{
 		Username:    "roleuser",
-		Password:    "pass12345",
+		Password:    "pass123456789",
 		AccountType: "human",
 	})
 	if err != nil {