feat(12.2-02): add file removal, caption, reorder and protected downloads

- DELETE, PUT and POST reorder under .../{id}/files/{field}, each scoped by one parent query (404 for a foreign file)
- protected download and thumb routes: is_public=false only, nosniff, private no-store, sandbox CSP, inline only for jpeg/png/gif/webp
- the save applies deferred removals, replaces attachOne files and rechecks maxFiles and required
- blobs of deleted files are removed after commit
- swagger2openapi emits binary content for file responses
- admin OpenAPI, TS types, conformance, README and attachments docs

modules/cabana/crud.go

@@ -13,6 +13,8 @@ import (
 
 	"git.golem15.com/golem15/summercms/modules/lagoon"
 	"git.golem15.com/golem15/summercms/modules/pact"
+	"git.golem15.com/golem15/summercms/modules/phrasebook"
+	"gocloud.dev/blob"
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
 )
@@ -20,6 +22,11 @@ import (
 // CRUDService runs schema-projected record and bulk operations.
 type CRUDService struct {
 	DB *gorm.DB
+
+	// bucket deletes the blobs of files a save replaces or removes, after
+	// commit; tr localizes the file limit messages. Both may be nil.
+	bucket *blob.Bucket
+	tr     *phrasebook.Translator
 }
 
 // RecordInput is a decoded JSON object. Keys are untrusted. SessionKey is