### Overview When a component instance populates an entity-reference input — most commonly an image `src` backed by an image/file reference — and the host config (e.g. a `ContentTemplate` or `PageRegion`) is translated, the affected component fails to render in the non-default language. An exception is thrown during component rendering and logged (`canvas`, severity Error); the component is broken (renders empty / as an error) while the rest of the page still loads: > `Twig\Error\RuntimeError` … `[<component>/src] NULL value found, but a string or an object is required.` The cause is in how component input translatability is decided. Translatability is derived from the input's **JSON Schema shape** alone. An image `src` has a translatable-looking shape (a URI-reference string), so it is exposed as translatable to config translation — even though it is actually populated by an **entity reference**, not author-entered text. There is no widget to translate it, but the translation workflow still stores a value for it, which is empty/`NULL`. That empty value lands in the language config override and shadows the base reference, so the resolved input is `NULL` at render time. Identified during !1099 but never tracked as its own bug. ### Steps to reproduce 1. Install Canvas; add a second language and a config-translation workflow (e.g. `tmgmt_config`). 2. Use a `ContentTemplate` (or `PageRegion`) containing a component whose image `src` is populated by an image reference (e.g. `card-with-local-image` / `card-with-stream-wrapper-image`). 3. Translate that config into the second language via the TMGMT / config-translation UI. The image is never offered for translation, yet an empty value is saved for it. 4. View the entity in the second language → the component fails to render and the Twig `RuntimeError` above is logged. (See the "Card with local image" example in !1099 for the exact before/after override YAML.) ### Proposed resolution Treat reference-backed inputs as non-translatable. Determine an input's translatability from its field-type prop expression (whether it resolves to an entity reference) rather than from its JSON Schema shape alone. Entity-reference inputs (`entity_reference`, `image`, `file`, media references) are no longer exposed for translation, so no empty override is stored and the translated component renders correctly. Inputs that merely *look* like URIs but hold author-entered literals (e.g. a remote-image `src` that stores a literal URL string) stay translatable. This aligns with ADR 0010: config translations may only hold translatable strings. ### Remaining tasks - Exclude entity-reference-backed inputs from translatability. - Add regression coverage for an entity-reference input (translatable shape, non-translatable value) alongside the existing translatable-shape scenarios. ### Data model changes The config schema that determines which component-tree inputs are translatable is derived dynamically at runtime (it is not stored). This fix changes that derived schema: entity-reference-backed inputs (e.g. an image `src`) are no longer part of the translatable schema.