docs: retire migrated working material and clarify documentation ownership

Remove migrated investigation and security documents, repair their incoming links, and align the English/Chinese READMEs with current module and release boundaries. Track AGENTS.md as the shared repository guide and make CLAUDE.md import it; keep working artifacts outside the repository.

Publish pgsty/silo.pgsty.com commit c7682185e2832b981629e1c17aef74fc778c6ca1 before publishing this cleanup: the new documentation routes are not live yet.

Validation: make rebrand-guard; 92 Markdown files checked for deletion-induced broken relative paths; 199 source-to-site references and anchors resolve in the paired site build; git diff --check.
Signed-off-by: Feng Ruohang <rh@vonng.com>

buildscripts/rebrand-guard/compat-baseline.json

@@ -132,7 +132,6 @@
     "MINIO_API_DELETE_CLEANUP_INTERVAL",
     "MINIO_API_DISABLE_ODIRECT",
     "MINIO_API_GZIP_OBJECTS",
-    "MINIO_API_LEGACY_BUCKET_RESOURCE_MATCH",
     "MINIO_API_LIST_QUORUM",
     "MINIO_API_OBJECT_MAX_VERSIONS",
     "MINIO_API_ODIRECT",
@@ -627,7 +626,6 @@
     "x-minio-origin-endpoint",
     "x-minio-prefixes-total",
     "x-minio-read-quorum",
-    "x-minio-replication",
     "x-minio-replication-actual-object-size",
     "x-minio-replication-delete-status",
     "x-minio-replication-deletemarker-status",

buildscripts/rebrand-guard/main.go

@@ -115,9 +115,8 @@ func collect(repo string) (manifest, error) {
 	fset := token.NewFileSet()
 
 	for _, rel := range files {
-		// Investigation artifacts contain synthetic routes and archived configurations.
+		// Migration notes and guard fixtures contain archived identifiers.
 		if rel == "SILO_REBRANDING_MIGRATION.md" ||
-			strings.HasPrefix(rel, "docs/investigations/") ||
 			strings.HasPrefix(rel, "buildscripts/rebrand-guard/") ||
 			strings.HasPrefix(rel, "buildscripts/helm-migration-guard/") {
 			continue