docs: adopt the no-CLA plus DCO policy and fix copyright terms

Brings the server in line with the contribution and copyright policy
already adopted in pgsty/mc.

Copyright terms were derived from the clock: startupBanner overwrote the
ldflags-injected CopyrightYear with time.Now().Year() and printed it as
the end of MinIO, Inc.'s term, so every January would have extended the
upstream copyright claim past the 2025 end of upstream development, and
release builds silently discarded the injected year. Both banners now
credit MinIO, Inc. for 2015-2025 and PGSTY from 2025 through the
release-stamped year, falling back to the current year in source builds.
NOTICE names PGSTY as the holder of the fork's modifications, matching
the banners and the packaging vendor field.

Contributions are accepted inbound=outbound under AGPL-3.0-or-later with
no CLA - the core is Copyright MinIO, Inc., so the combined work can
never be relicensed and a CLA would buy nothing. What a fork carrying a
downstream delta does need is provenance, so DCO 1.1 sign-off is now
mandatory and enforced by a workflow that rejects unsigned non-bot
commits. CONTRIBUTING documents sign-off, repair, cherry-pick provenance,
dual copyright headers, trailer preservation across squash merges, and
that assistive-tooling trailers carry no authorship or copyright claim.

verify-rebrand.sh pins the copyright split and the policy files so
neither can regress.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Signed-off-by: Feng Ruohang <rh@vonng.com>

cmd/build-constants.go

@@ -17,7 +17,30 @@
 
 package cmd
 
-import "runtime"
+import (
+	"runtime"
+	"strconv"
+	"time"
+)
+
+// upstreamCopyrightEndYear is the last year of upstream MinIO, Inc. development
+// this fork derives from. It is fixed: the fork's own maintenance does not
+// extend the upstream copyright term.
+const upstreamCopyrightEndYear = "2025"
+
+// forkCopyrightStartYear is the year the Silo fork began.
+const forkCopyrightStartYear = "2025"
+
+// copyrightEndYear returns the end year shown in copyright notices for the
+// fork's own modifications. Release builds inject CopyrightYear through
+// ldflags; source builds keep the "0000" placeholder, for which the current
+// year is used instead.
+func copyrightEndYear() string {
+	if CopyrightYear == "" || CopyrightYear == "0000" {
+		return strconv.Itoa(time.Now().Year())
+	}
+	return CopyrightYear
+}
 
 // DO NOT EDIT THIS FILE DIRECTLY. These are build-time constants
 // set through ‘buildscripts/gen-ldflags.go’.

cmd/main.go

@@ -25,9 +25,7 @@ import (
 	"runtime"
 	"runtime/debug"
 	"sort"
-	"strconv"
 	"strings"
-	"time"
 
 	"github.com/minio/cli"
 	"github.com/minio/minio/internal/color"
@@ -176,9 +174,8 @@ func newApp(name string) *cli.App {
 }
 
 func startupBanner(banner io.Writer) {
-	CopyrightYear = strconv.Itoa(time.Now().Year())
-	fmt.Fprintln(banner, color.Blue("Copyright:")+color.Bold(" 2015-%s MinIO, Inc.", CopyrightYear))
-	fmt.Fprintln(banner, color.Blue("Modifications:")+color.Bold(" Copyright 2026 PGSTY contributors"))
+	fmt.Fprintln(banner, color.Blue("Copyright:")+color.Bold(" 2015-%s MinIO, Inc.", upstreamCopyrightEndYear))
+	fmt.Fprintln(banner, color.Blue("Modifications:")+color.Bold(" Copyright %s-%s PGSTY", forkCopyrightStartYear, copyrightEndYear()))
 	fmt.Fprintln(banner, color.Blue("License:")+color.Bold(" "+MinioLicense))
 	fmt.Fprintln(banner, color.Blue("Version:")+color.Bold(" %s (%s %s/%s)", ReleaseTag, runtime.Version(), runtime.GOOS, runtime.GOARCH))
 }
@@ -188,8 +185,8 @@ func versionBanner(c *cli.Context) io.Reader {
 	fmt.Fprintln(banner, color.Bold("%s version %s (commit-id=%s)", c.App.Name, c.App.Version, CommitID))
 	fmt.Fprintln(banner, color.Blue("Runtime:")+color.Bold(" %s %s/%s", runtime.Version(), runtime.GOOS, runtime.GOARCH))
 	fmt.Fprintln(banner, color.Blue("License:")+color.Bold(" GNU AGPLv3 - https://www.gnu.org/licenses/agpl-3.0.html"))
-	fmt.Fprintln(banner, color.Blue("Copyright:")+color.Bold(" 2015-%s MinIO, Inc.", CopyrightYear))
-	fmt.Fprintln(banner, color.Blue("Modifications:")+color.Bold(" Copyright 2026 PGSTY contributors"))
+	fmt.Fprintln(banner, color.Blue("Copyright:")+color.Bold(" 2015-%s MinIO, Inc.", upstreamCopyrightEndYear))
+	fmt.Fprintln(banner, color.Blue("Modifications:")+color.Bold(" Copyright %s-%s PGSTY", forkCopyrightStartYear, copyrightEndYear()))
 	fmt.Fprintln(banner, color.Blue("Source compatibility:")+color.Bold(" based on MinIO technology"))
 	return strings.NewReader(banner.String())
 }