fix: preserve outbound thread sessions

docs/.generated/plugin-sdk-api-baseline.sha256

@@ -1,2 +1,2 @@
-3a2cde4b15041b5456420b2052b572f9968a93690814d2cf924382fd2f54d1d3  plugin-sdk-api-baseline.json
-38cd9086be93fc9531a8036812c197118c7830d52d40424be08dc9c6d51092e2  plugin-sdk-api-baseline.jsonl
+d7f6e6ecdfb78c73760689af5a684c20ec7ca28509d4f63bf0d990a2d739c6ce  plugin-sdk-api-baseline.json
+584681e4436a4e84c2ff20196ff194a63915caf4dda70de9c27f34ab0d7bde0b  plugin-sdk-api-baseline.jsonl

docs/plugins/sdk-channel-plugins.md

@@ -176,6 +176,12 @@ surfaces:
 - `openclaw/plugin-sdk/outbound-media` and
   `openclaw/plugin-sdk/outbound-runtime` for media loading plus outbound
   identity/send delegates and payload planning
+- `buildThreadAwareOutboundSessionRoute(...)` from
+  `openclaw/plugin-sdk/channel-core` when an outbound route should preserve an
+  explicit `replyToId`/`threadId` or recover the current `:thread:` session
+  after the base session key still matches. Provider plugins can override
+  precedence, suffix behavior, and thread id normalization when their platform
+  has native thread delivery semantics.
 - `openclaw/plugin-sdk/thread-bindings-runtime` for thread-binding lifecycle
   and adapter registration
 - `openclaw/plugin-sdk/agent-media-payload` only when a legacy agent/media