fix: remove the fragmentation handling stranded by #1303

#1298 and #1303 merged together. #1298 taught the creation paths to
resolve a fragmentation_level default; #1303 removed everything that
consumed it. Neither conflicted textually, so main ended up validating
the field on create and update, copying it on duplicate, resolving
default_fragmentation_level for it, and advertising it in the v1 API
docs — for a value nothing reads and a setting the Image Security tab no
longer exposes.

Inert rather than broken, which is exactly why it needed removing on
purpose: dead code that contradicts the PR that just deleted the feature
is how the next reader concludes fragmentation still works.

The events.fragmentation_level column and the app_settings row stay, as
#1303 decided — dropping a column is irreversible and the stored values
are harmless once nothing reads them.

Refs #1300

backend/src/routes/adminEvents/crud.js

@@ -235,7 +235,6 @@ module.exports = (router) => {
     body('protection_level').optional().not().isArray().isIn(['basic', 'standard', 'enhanced', 'maximum']),
     body('use_canvas_rendering').optional().not().isArray().isBoolean().toBoolean(),
     body('image_quality').optional().not().isArray().isInt({ min: 1, max: 100 }).toInt(),
-    body('fragmentation_level').optional().not().isArray().isInt({ min: 1, max: 10 }).toInt(),
     body('watermark_downloads').optional().isBoolean(),
     body('watermark_text').optional().trim(),
     // #328 follow-up: per-event opt-in for presigned-URL "Download All".
@@ -1427,7 +1426,6 @@ module.exports = (router) => {
         protection_level: source.protection_level,
         image_quality: source.image_quality,
         use_canvas_rendering: source.use_canvas_rendering,
-        fragmentation_level: source.fragmentation_level,
         watermark_downloads: source.watermark_downloads,
         watermark_text: source.watermark_text,
         allow_presigned_download: source.allow_presigned_download,

backend/src/routes/adminEvents/helpers.js

@@ -127,7 +127,6 @@ const getDownloadProtectionDefaults = async () => {
  *   default_protection_level     → events.protection_level
  *   default_image_quality        → events.image_quality
  *   enable_canvas_rendering      → events.use_canvas_rendering
- *   default_fragmentation_level  → events.fragmentation_level
  *
  * Each maps onto a column migration 038 already created, and each is
  * labelled "… by default", so applying them at creation is what the panel
@@ -172,7 +171,6 @@ const getImageSecurityDefaults = async (trx = null) => {
         'default_protection_level',
         'default_image_quality',
         'enable_canvas_rendering',
-        'default_fragmentation_level',
       ])
       .select('setting_key', 'setting_value');
 
@@ -214,10 +212,6 @@ const getImageSecurityDefaults = async (trx = null) => {
       defaults.use_canvas_rendering = canvas;
     }
 
-    const fragmentation = toInteger(read('default_fragmentation_level'));
-    if (fragmentation !== undefined && fragmentation >= 1 && fragmentation <= 10) {
-      defaults.fragmentation_level = fragmentation;
-    }
   } catch (error) {
     // A settings read must never block event creation; the column defaults
     // are a correct fallback.
@@ -262,8 +256,6 @@ const resolveImageSecurityColumns = (body = {}, defaults = {}) => {
   const canvas = pick('use_canvas_rendering');
   if (canvas !== undefined) columns.use_canvas_rendering = formatBoolean(canvas);
 
-  const fragmentation = pick('fragmentation_level');
-  if (fragmentation !== undefined) columns.fragmentation_level = fragmentation;
 
   return columns;
 };

backend/src/routes/v1/events.js

@@ -138,7 +138,6 @@ const photoUpload = async (req, res, next) => {
  *               protection_level: { type: string, nullable: true, enum: [basic, standard, enhanced, maximum], description: "Image protection level. When omitted, falls back to the global default_protection_level setting." }
  *               use_canvas_rendering: { type: boolean, nullable: true, description: "Render gallery images to a canvas instead of an img tag. When omitted, falls back to the global enable_canvas_rendering setting." }
  *               image_quality: { type: integer, minimum: 1, maximum: 100, nullable: true, description: "Served image quality percentage. When omitted, falls back to the global default_image_quality setting." }
- *               fragmentation_level: { type: integer, minimum: 1, maximum: 10, nullable: true, description: "Stored for future use; no renderer consumes it yet. When omitted, falls back to the global default_fragmentation_level setting." }
  *               hero_logo_visible: { type: boolean, nullable: true, description: "Show event logo in the hero block. When omitted, falls back to the global branding_logo_display_hero setting." }
  *               hero_logo_size: { type: string, nullable: true, enum: [small, medium, large, xlarge], description: "Hero logo size. When omitted, falls back to the global branding_logo_size setting." }
  *               hero_logo_position: { type: string, nullable: true, enum: [top, center, bottom], description: "Hero logo position. Defaults to 'top' (not settings-backed — see migration 084)." }
@@ -187,7 +186,6 @@ router.post(
     body('protection_level').optional().not().isArray().isIn(['basic', 'standard', 'enhanced', 'maximum']),
     body('use_canvas_rendering').optional().not().isArray().isBoolean().toBoolean(),
     body('image_quality').optional().not().isArray().isInt({ min: 1, max: 100 }).toInt(),
-    body('fragmentation_level').optional().not().isArray().isInt({ min: 1, max: 10 }).toInt(),
     body('hero_logo_visible').optional().isBoolean(),
     body('hero_logo_size').optional().isIn(['small', 'medium', 'large', 'xlarge']),
     body('hero_logo_position').optional().isIn(['top', 'center', 'bottom'])