feat: add view_update event type (#355)

* feat(rum): add view_update event type and _view-properties shared schema

Implements the view_update event type per the approved RFC on RUM Event
Format limitations. The new event carries only changed view fields,
eliminating the 50-90% redundant data sent with every full view update.

Key changes:
- Add schemas/rum/_view-properties.json: shared optional view-specific
  properties (no required fields) composed by both view and view_update
- Add schemas/rum/view_update-schema.json: standalone schema (no
  _common-schema.json ref) with minimal required set: type, application.id,
  session.id, view.id, _dd.document_version
- Refactor schemas/rum/view-schema.json to reference _view-properties.json,
  slimming its last allOf block to type and _dd.document_version only
- Add view_update to oneOf in rum-events-schema.json,
  rum-events-browser-schema.json, and rum-events-mobile-schema.json
- Add samples/rum-events/view_update.json sample event
- Regenerate TypeScript types: RumViewUpdateEvent exported in lib/generated/rum.ts

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

* fix(rum): align account.id required and rebuild with tsc 5.9.3

Two fixes for failing CI checks:

1. ios-sdk-test: The Swift code generator creates a single shared
   RUMAccount struct across all event schemas. view_update had
   account.id as optional while all other events (via _common-schema.json)
   have it required, causing an inconsistency error. Adding required: ["id"]
   to account in view_update-schema.json resolves the conflict.

2. check-is-built: Local node_modules had tsc 4.7.4 (stale, pre-yarn-install)
   while yarn.lock pins tsc 5.9.3. The two versions emit different declaration
   file syntax (export declare type vs export type), causing the committed
   lib/ files to not match CI's build output. Rebuilding with the correct
   tsc 5.9.3 after running yarn install fixes the mismatch.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

* fix(rum): align view_update shared struct definitions with _common-schema

The iOS Swift code generator requires all uses of a named struct (Session,
View, OS, Device) across event schemas to have identical field definitions.
Four conflicts remained after the previous fix:

- Device.locale/locales/timeZone: descriptions in _common-schema.json use
  U+2019 (curly right single quote) while view_update used plain ASCII
  apostrophes (U+0027). Fixed by copying the exact characters.
- Session: _common-schema requires both id and type; view_update only
  required id. Added type to session.required.
- View: _common-schema requires id and url; view_update only required id.
  Added url to view.required and updated the sample accordingly.
- OS: _common-schema requires name, version, version_major; view_update
  had no required fields. Added the matching required array.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

* fix(rum): apply prettier formatting to view_update files

Python's json.dump produced non-Prettier-compliant formatting in
view_update-schema.json and view_update.json. Running yarn format -w
to fix.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

* fix(rum): copy exact device descriptions from _common-schema.json

Previous fix over-replaced ASCII apostrophes with U+2019 in device
descriptions, converting example quote chars around 'en-US' and
'Europe/Berlin' as well. _common-schema.json only uses U+2019 for
possessive apostrophes (user's, device's), not for example quotes.
Copying descriptions verbatim from _common-schema.json to ensure
byte-identical strings and resolve the Swift shared struct conflict.

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

* fix(rum): address review feedback on view_update schema

- view_update: use _common-schema.json directly; session.type, view.url
  and _dd.format_version are required alongside the delta payload
- view_update: make date required; remove required on sub-object fields
  (connectivity.status, display.viewport dims, os fields) that block
  partial updates
- view-schema: restore required constraints removed by refactor
  (view.time_spent, action/error/resource.count, privacy.replay_level,
  display.scroll fields)
- view-schema: move view-specific _dd properties (page_states,
  replay_stats, cls, configuration, profiling) out of _view-properties
  and into view-schema to eliminate _dd namespace collision with
  view_update
- sample: update view_update.json to reflect minimal delta payload

* fix: move required constraints into _view-properties.json to avoid Android generator merge conflict

The Android SDK model generator cannot merge Enum with Primitive(type=STRING).
Previously, view-schema.json had typed stubs for privacy.replay_level and
display.scroll.* properties that conflicted with their enum/typed definitions
in _view-properties.json when the Android generator resolved the allOf merge.

Move the required constraints directly into _view-properties.json and remove
the typed property stubs from view-schema.json's inline allOf block. This
eliminates the merge conflict entirely since _view-properties.json is a single
source of truth for these properties.

* fix: replace empty stubs with typed stubs to fix Android generator crash

The Android schema generator does not support empty {} schema definitions
(all-null JsonDefinition). The view-schema.json stubs for time_spent ({})
and action/error/resource ({ required: [count] }) caused the generator to
crash with 'Unsupported schema definition'.

- Replace {} and bare-required stubs with typed stubs ({ type: integer }
  and { type: object }) so the generator sees a concrete type to work with
- Move required:[count] for action/error/resource into _view-properties.json
  alongside their property definitions, per reviewer suggestion

The outer view.required:[time_spent,action,error,resource] stays in
view-schema.json since view_update uses _view-properties.json and those
fields must remain optional for delta events.

* refactor: remove redundant property type stubs from view-schema.json

* Revert "refactor: remove redundant property type stubs from view-schema.json"

This reverts commit 9fa7961.

* fix required in some places (#360)

* fix build

* rename _view-properties.json to _view-properties-schema.json to match naming convention

---------

Co-authored-by: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>
Co-authored-by: Sasha Gringauz <aleksandr.gringauz@datadoghq.com>

Author: 3 people

lib/cjs/generated/rum.d.ts

@@ -0,0 +1,12 @@
+{
+  "type": "view_update",
+  "date": 1712345678901,
+  "application": { "id": "ac8218cf-498b-4d33-bd44-151095959547" },
+  "session": { "id": "cacbf45c-3a05-48ce-b066-d76349460599", "type": "user" },
+  "view": {
+    "id": "623d50fd-75cf-4025-97d2-e51ff94171f6",
+    "url": "https://example.com/home",
+    "time_spent": 245512755000
+  },
+  "_dd": { "document_version": 2, "format_version": 2 }
+}

lib/esm/generated/rum.d.ts

@@ -23,6 +23,9 @@
     {
       "$ref": "rum/view-schema.json"
     },
+    {
+      "$ref": "rum/view_update-schema.json"
+    },
     {
       "title": "RumVitalEvent",
       "oneOf": [

samples/rum-events/view_update.json

@@ -20,6 +20,9 @@
     {
       "$ref": "rum/view-schema.json"
     },
+    {
+      "$ref": "rum/view_update-schema.json"
+    },
     {
       "title": "RumVitalEvent",
       "oneOf": [

schemas/rum-events-browser-schema.json

@@ -23,6 +23,9 @@
     {
       "$ref": "rum/view-schema.json"
     },
+    {
+      "$ref": "rum/view_update-schema.json"
+    },
     {
       "title": "RumVitalEvent",
       "oneOf": [