fix(milestone): address milestones by title or ID everywhere

milestone view v2.0 failed with "invalid resource number" although its
usage promised <id-or-name>, and issue create --milestone v1.0 failed
with a strconv error. Every milestone argument (view, edit, delete,
close, reopen, milestone issue add|remove|list) and issue create|edit
-m/--milestone now accept a title or an ID: a number is an ID first,
then a title; --by-name matches numeric titles only. --milestone-name
stays as a hidden name of --milestone, and issue edit gains
--remove-milestone (as does --milestone 0).

Signed-off-by: bircni <bircni@icloud.com>

internal/app/milestone_bulk_test.go

@@ -17,9 +17,13 @@ import (
 func TestBulkMilestoneStateContinuesAfterFailureAndKeepsJSONClean(t *testing.T) {
 	mutations := []string{}
 	server := newAuthenticatedServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/api/v1/repos/alice/project/milestones" {
+			writeMilestones(w, r, `[{"id":9,"title":"v9"},{"id":10,"title":"v10"},{"id":11,"title":"v11"}]`)
+			return
+		}
 		id := strings.TrimPrefix(r.URL.Path, "/api/v1/repos/alice/project/milestones/")
 		if r.Method == http.MethodGet {
-			_, _ = fmt.Fprintf(w, `{"id":%s,"title":"Milestone %s"}`, id, id)
+			_, _ = fmt.Fprintf(w, `{"id":%s,"title":"v%s"}`, id, id)
 			return
 		}
 		mutations = append(mutations, id)
@@ -32,7 +36,7 @@ func TestBulkMilestoneStateContinuesAfterFailureAndKeepsJSONClean(t *testing.T)
 	defer server.Close()
 	deps, out, diagnostics := serverDeps(t, server.URL)
 	err := Execute(context.Background(), deps, []string{"milestone", "close", "9", "10", "11", "-R", "alice/project", "--json=id,state"})
-	require.ErrorContains(t, err, "milestone 10")
+	require.ErrorContains(t, err, "milestone v10")
 	require.Equal(t, clierr.Failure, clierr.ExitCode(err))
 	require.Equal(t, []string{"9", "10", "11"}, mutations)
 	require.JSONEq(t, `[{"id":9,"state":"closed"},{"id":11,"state":"closed"}]`, out.String())
@@ -40,7 +44,7 @@ func TestBulkMilestoneStateContinuesAfterFailureAndKeepsJSONClean(t *testing.T)
 	mutations = nil
 	out.Reset()
 	err = Execute(context.Background(), deps, []string{"milestone", "close", "9", "bad", "-R", "alice/project"})
-	require.Equal(t, clierr.Usage, clierr.ExitCode(err))
+	require.ErrorContains(t, err, `milestone "bad" not found in alice/project`)
 	require.Empty(t, mutations)
 	require.Empty(t, out.String())
 }