[CHA-2961] Webhook handling spec — regenerate SDK + dual-API (#62)

* feat(webhook): regenerate with CHA-2961 helpers + dual-API on StreamSDKClient

Regenerated Webhook.java + WebhookTest.java from chat/'s
feature/cha-2961-webhook-handling-spec branch.

New surface in io.getstream.Webhook:
- UnknownEvent class (forward-compat for unknown event types)
- gunzipPayload, decodeSqsPayload, decodeSnsPayload primitives
- parseEvent (returns typed event or UnknownEvent)
- verifyAndParseWebhook HTTP composite
- parseSqsPayload, parseSnsPayload queue composites (no signature)
- InvalidWebhookException (unified exception per spec rev 2026-05-11)

Hand-added instance methods on StreamSDKClient (dual API):
- verifySignature(body, signature) — uses client's stored secret
- verifyAndParseWebhook(body, signature) — uses client's stored secret

generate.sh now also runs chat-manager's generate-webhook-fixtures
subcommand to populate src/test/resources/fixtures/webhooks/.

Refs CHA-2961.

* chore: re-regenerate against updated chat/ templates (parseSqs/parseSns rename)

* feat(webhook): add parseSqs/parseSns instance methods on StreamSDKClient

* chore: regenerate webhook helpers with base64 fallback for plain-JSON SQS

* chore: regenerate with P7 chat/ template fixes; rename InvalidWebhookException → WebhookException in StreamSDKClient

Exception class was split per spec §5.2 in chat/ 13097a0765 into a
WebhookException base + InvalidSignatureException / MalformedWebhookException
subclasses. The instance methods on StreamSDKClient declare 'throws' clauses
that referenced the old unified class name; updated to the new base class so
both subclasses propagate cleanly.

* chore: regenerate with unified InvalidWebhookError; rename Webhook.WebhookException → Webhook.InvalidWebhookError in StreamSDKClient

* chore: regenerate with P9 chat/ template fixes (WebhookHelpers wire, fixtures-present guard, WebhookException deprecation alias)

* chore: regenerate after chat/ restructure (build/chat-manager path)

Author: mogita

CHANGELOG.md

@@ -2,6 +2,31 @@
 
 All notable changes to this project will be documented in this file. See [standard-version](https://github.com/conventional-changelog/standard-version) for commit guidelines.
 
+## [Unreleased]
+
+### Added
+
+- Webhook handling spec helpers (CHA-2961): `UnknownEvent` class for forward-compat;
+  `gunzipPayload`, `decodeSqsPayload`, `decodeSnsPayload` primitives;
+  `verifyAndParseWebhook` HTTP composite; `parseSqs` / `parseSns`
+  queue composites (no HMAC signature on the payload — queue transports rely on
+  AWS IAM for authentication). Transparent gzip via magic-byte detection.
+- New instance methods on `StreamSDKClient`: `verifySignature(body, signature)`
+  and `verifyAndParseWebhook(body, signature)` — drop the api_secret parameter
+  in favor of the client's stored secret. Dual API: static `Webhook.*` methods
+  remain available.
+- New instance methods on `StreamSDKClient`: `parseSqs(String)`, `parseSns(String)`
+  (no signature; AWS IAM).
+- New exception class: `Webhook.InvalidWebhookException` (unified — covers both
+  signature mismatch and malformed payloads).
+- Conformance fixture suite under `src/test/resources/fixtures/webhooks/`.
+
+### Changed
+
+- No breaking changes. All existing webhook helpers preserved.
+
+[Spec](https://www.notion.so/stream-wiki/Server-Side-SDK-Webhook-Handling-Spec-34b6a5d7f9f681e78003c443f227493c)
+
 ## [7.2.0](https://github.com/GetStream/stream-sdk-java/compare/7.1.0...7.2.0) (2026-04-30)
 
 ## [7.1.0](https://github.com/GetStream/stream-sdk-java/compare/7.0.0...7.1.0) (2026-04-10)

generate.sh

@@ -11,7 +11,11 @@ fi
 set -ex
 
 # cd in API repo, generate new spec and then generate code from it
-( cd $SOURCE_PATH ; make openapi ; go run ./cmd/chat-manager openapi generate-client --language java --spec ./releases/v2/serverside-api.yaml --output ../stream-sdk-java )
+( cd $SOURCE_PATH ; make openapi ; ./build/chat-manager openapi generate-client --language java --spec ./releases/v2/serverside-api.yaml --output ../stream-sdk-java )
+
+# Generate webhook conformance fixtures (CHA-2961). The test template reads them from
+# src/test/resources/fixtures/webhooks/ and gracefully skips if the dir is missing.
+( cd $SOURCE_PATH ; ./build/chat-manager openapi generate-webhook-fixtures --output ../stream-sdk-java/src/test/resources/fixtures/webhooks )
 
 perl -i -0pe 's/    \@JsonProperty\("Role"\)\n    private String role;\n//g' src/main/java/io/getstream/models/CallParticipant.java