fix: tighten group elevated targeting

docs/gateway/configuration.md

@@ -319,6 +319,7 @@ Group messages default to **require mention** (either metadata mention or regex
 - **Metadata mentions**: Native platform @-mentions (e.g., WhatsApp tap-to-mention). Ignored in WhatsApp self-chat mode (see `whatsapp.allowFrom`).
 - **Text patterns**: Regex patterns defined in `mentionPatterns`. Always checked regardless of self-chat mode.
 - Mention gating is enforced only when mention detection is possible (native mentions or at least one `mentionPattern`).
+ - Per-agent override: `routing.agents.<agentId>.mentionPatterns` (useful when multiple agents share a group).
 
 ```json5
 {
@@ -331,6 +332,18 @@ Group messages default to **require mention** (either metadata mention or regex
 }
 ```
 
+Per-agent override (takes precedence when set, even `[]`):
+```json5
+{
+  routing: {
+    agents: {
+      work: { mentionPatterns: ["@workbot", "\\+15555550123"] },
+      personal: { mentionPatterns: ["@homebot", "\\+15555550999"] }
+    }
+  }
+}
+```
+
 Mention gating defaults live per provider (`whatsapp.groups`, `telegram.groups`, `imessage.groups`, `discord.guilds`). When `*.groups` is set, it also acts as a group allowlist; include `"*"` to allow all groups.
 
 To respond **only** to specific text triggers (ignoring native @-mentions):