docs: update GLOSSARY for JourneyItem view types; add ADR-035

Fixes GLOSSARY position-step value (1000→10), adds DEFERRABLE constraint note,
and documents GeschichteView, JourneyItemView, and DocumentSummary read-model types.

ADR-035 records the decision to use Optional<String> for three-way PATCH semantics
instead of jackson-databind-nullable (which targets Jackson 2.x and is incompatible
with Spring Boot 4.0 / Jackson 3.x).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docs/GLOSSARY.md

@@ -151,7 +151,13 @@ _See also [Chronik](#chronik-internal)._
 
 **Geschichte** (`Geschichte`) `[user-facing]` — a narrative story or curated document journey published in the archive. Two subtypes: `STORY` (free-form prose linking `Person`s) and `JOURNEY` (a *Lesereise* — an ordered sequence of `JourneyItem`s). Lifecycle: `DRAFT → PUBLISHED` (see `GeschichteStatus`). DRAFT stories are hidden from users without the `BLOG_WRITE` permission.
 
-**JourneyItem** (`JourneyItem`, table `journey_items`) `[internal]` — a single stop in a *Lesereise* (`Geschichte` with `type=JOURNEY`). Either document-backed (`document_id IS NOT NULL`) or a note-only interlude (`note IS NOT NULL`). Ordered by `position` (gaps of 1000 leave room for drag-reorder). A CHECK constraint ensures at least one of `document_id` or `note` is present. The FK to `documents` uses `ON DELETE SET NULL`, so deleting a document preserves the item (with `document_id = null`).
+**JourneyItem** (`JourneyItem`, table `journey_items`) `[internal]` — a single stop in a *Lesereise* (`Geschichte` with `type=JOURNEY`). Either document-backed (`document_id IS NOT NULL`) or a note-only interlude (`note IS NOT NULL`). Ordered by `position` (step of 10; max 100 items per journey). A DEFERRABLE UNIQUE constraint on `(geschichte_id, position)` allows atomic position swaps in the same transaction. A CHECK constraint ensures at least one of `document_id` or `note` is present. The FK to `documents` uses `ON DELETE SET NULL`, so deleting a document preserves the item (with `document_id = null`).
+
+**GeschichteView** (`GeschichteView`) `[internal]` — lean read-model record returned by `GeschichteService.getById()`. Contains `AuthorView` (id + displayName only — email not exposed) and a `List<JourneyItemView>` loaded via a separate query rather than a lazy collection.
+
+**JourneyItemView** (`JourneyItemView`) `[internal]` — lean view record for a single `JourneyItem` surface, containing `id`, `position`, an optional `DocumentSummary`, and an optional `note`.
+
+**DocumentSummary** (`DocumentSummary`) `[internal]` — lean document read-model used inside `JourneyItemView`. Contains title, date, senderName, receiverName, receiverCount, datePrecision — no tags or file storage info.
 
 **Lesereise** `[user-facing]` — a curated reading journey through a sequence of family documents, optionally annotated with editorial notes. Implemented as a `Geschichte` with `type=JOURNEY`. The reader UI (follow-on issue) renders items as a sequential reading experience.
 

docs/adr/035-optional-string-three-way-patch-semantics.md

@@ -0,0 +1,43 @@
+# ADR-035 — `Optional<String>` for three-way PATCH semantics
+
+**Status:** Accepted  
+**Date:** 2026-06-08  
+**Issue:** #751 (JourneyItem CRUD API)
+
+## Context
+
+The `PATCH /api/geschichten/{id}/items/{itemId}` endpoint must distinguish three cases for the `note` field:
+
+| JSON body         | Intended meaning      |
+|-------------------|-----------------------|
+| `{"note": "text"}`| Set note to "text"    |
+| `{"note": null}`  | Clear the note        |
+| `{}` (absent)     | Leave note unchanged  |
+
+The standard library for this on Jackson 2.x is `jackson-databind-nullable` (`JsonNullable<T>` from `org.openapitools`). However, that library targets `com.fasterxml.jackson.*` (Jackson 2.x) and is incompatible with Spring Boot 4.0 / Spring Framework 7, which uses `tools.jackson.*` (Jackson 3.x). The module fails to register and throws at startup.
+
+## Decision
+
+Use `Optional<String>` with Java's default field initializer (`= null`) to encode the three states:
+
+```java
+@Data
+public class JourneyItemUpdateDTO {
+    private Optional<String> note = null;  // Java default — absent = no-op
+}
+```
+
+| Java value         | JSON wire         | Semantics     |
+|--------------------|-------------------|---------------|
+| `null` (default)   | field absent      | no-op         |
+| `Optional.empty()` | `{"note": null}`  | clear         |
+| `Optional.of("x")` | `{"note": "x"}`   | set           |
+
+Jackson 3.x natively maps a JSON `null` to `Optional.empty()` and leaves absent fields at their Java default. No custom module is needed.
+
+## Consequences
+
+- No external dependency for PATCH semantics — simpler pom.xml.
+- The DTO field type is `Optional<String>`, not `String` — service code must null-check the field first (`if (noteField == null) return;`) and then call `.orElse(null)` to unwrap.
+- This pattern applies to any future PATCH DTO that needs three-way semantics on a nullable field.
+- `jackson-databind-nullable` is removed from `pom.xml`; `JacksonConfig.java` is kept as a placeholder for future custom modules.