Docs: update gateway config reference for Slack and TTS

docs/gateway/configuration-reference.md

@@ -406,6 +406,7 @@ WhatsApp runs through the gateway's web channel (Baileys Web). It starts automat
         sessionPrefix: "slack:slash",
         ephemeral: true,
       },
+      typingReaction: "hourglass_flowing_sand",
       textChunkLimit: 4000,
       chunkMode: "length",
       streaming: "partial", // off | partial | block | progress (preview mode)
@@ -427,6 +428,8 @@ WhatsApp runs through the gateway's web channel (Baileys Web). It starts automat
 
 **Thread session isolation:** `thread.historyScope` is per-thread (default) or shared across channel. `thread.inheritParent` copies parent channel transcript to new threads.
 
+- `typingReaction` adds a temporary reaction to the inbound Slack message while a reply is running, then removes it on completion. Use a Slack emoji shortcode such as `"hourglass_flowing_sand"`.
+
 | Action group | Default | Notes                  |
 | ------------ | ------- | ---------------------- |
 | reactions    | enabled | React + list reactions |
@@ -1618,6 +1621,7 @@ Batches rapid text-only messages from the same sender into a single agent turn.
       },
       openai: {
         apiKey: "openai_api_key",
+        baseUrl: "https://api.openai.com/v1",
         model: "gpt-4o-mini-tts",
         voice: "alloy",
       },
@@ -1630,6 +1634,8 @@ Batches rapid text-only messages from the same sender into a single agent turn.
 - `summaryModel` overrides `agents.defaults.model.primary` for auto-summary.
 - `modelOverrides` is enabled by default; `modelOverrides.allowProvider` defaults to `false` (opt-in).
 - API keys fall back to `ELEVENLABS_API_KEY`/`XI_API_KEY` and `OPENAI_API_KEY`.
+- `openai.baseUrl` overrides the OpenAI TTS endpoint. Resolution order is config, then `OPENAI_TTS_BASE_URL`, then `https://api.openai.com/v1`.
+- When `openai.baseUrl` points to a non-OpenAI endpoint, OpenClaw treats it as an OpenAI-compatible TTS server and relaxes model/voice validation.
 
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