app: port app to use the system package

This commit does away with almost all baggage left over from the Ego port. Error wrapping also got simplified. All API changes happens to be internal which means no changes to main except renaming of the BaseError type.

Signed-off-by: Ophestra Umiker <cat@ophivana.moe>

error.go

@@ -6,11 +6,12 @@ import (
 	"os"
 
 	"git.ophivana.moe/cat/fortify/internal/app"
+	"git.ophivana.moe/cat/fortify/internal/fmsg"
 )
 
 func logWaitError(err error) {
-	var e *app.BaseError
-	if !app.AsBaseError(err, &e) {
+	var e *fmsg.BaseError
+	if !fmsg.AsBaseError(err, &e) {
 		fmt.Println("fortify: wait failed:", err)
 	} else {
 		// Wait only returns either *app.ProcessError or *app.StateStoreError wrapped in a *app.BaseError
@@ -31,7 +32,7 @@ func logWaitError(err error) {
 
 				// every error here is wrapped in *app.BaseError
 				for _, ei := range errs {
-					var eb *app.BaseError
+					var eb *fmsg.BaseError
 					if !errors.As(ei, &eb) {
 						// unreachable
 						fmt.Println("fortify: invalid error type returned by revert:", ei)
@@ -46,9 +47,9 @@ func logWaitError(err error) {
 }
 
 func logBaseError(err error, message string) {
-	var e *app.BaseError
+	var e *fmsg.BaseError
 
-	if app.AsBaseError(err, &e) {
+	if fmsg.AsBaseError(err, &e) {
 		fmt.Print("fortify: " + e.Message())
 	} else {
 		fmt.Println(message, err)