fix: harden WhatsApp structured object prompts

docs/channels/location.md

@@ -10,8 +10,8 @@ title: "Channel Location Parsing"
 
 OpenClaw normalizes shared locations from chat channels into:
 
-- human-readable text appended to the inbound body, and
-- structured fields in the auto-reply context payload.
+- terse coordinate text appended to the inbound body, and
+- structured fields in the auto-reply context payload. Channel-provided labels, addresses, and captions/comments are rendered into the prompt by the shared untrusted metadata JSON block, not inline in the user body.
 
 Currently supported:
 
@@ -26,16 +26,24 @@ Locations are rendered as friendly lines without brackets:
 - Pin:
   - `📍 48.858844, 2.294351 ±12m`
 - Named place:
-  - `📍 Eiffel Tower — Champ de Mars, Paris (48.858844, 2.294351 ±12m)`
+  - `📍 48.858844, 2.294351 ±12m`
 - Live share:
   - `🛰 Live location: 48.858844, 2.294351 ±12m`
 
-If the channel includes a caption/comment, it is appended on the next line:
+If the channel includes a label, address, or caption/comment, it is preserved in the context payload and appears in the prompt as fenced untrusted JSON:
 
+````text
+Location (untrusted metadata):
+```json
+{
+  "latitude": 48.858844,
+  "longitude": 2.294351,
+  "name": "Eiffel Tower",
+  "address": "Champ de Mars, Paris",
+  "caption": "Meet here"
+}
 ```
-📍 48.858844, 2.294351 ±12m
-Meet here
-```
+````
 
 ## Context fields
 
@@ -48,9 +56,12 @@ When a location is present, these fields are added to `ctx`:
 - `LocationAddress` (string; optional)
 - `LocationSource` (`pin | place | live`)
 - `LocationIsLive` (boolean)
+- `LocationCaption` (string; optional)
+
+The prompt renderer treats `LocationName`, `LocationAddress`, and `LocationCaption` as untrusted metadata and serializes them through the same bounded JSON path used for other channel context.
 
 ## Channel notes
 
 - **Telegram**: venues map to `LocationName/LocationAddress`; live locations use `live_period`.
-- **WhatsApp**: `locationMessage.comment` and `liveLocationMessage.caption` are appended as the caption line.
+- **WhatsApp**: `locationMessage.comment` and `liveLocationMessage.caption` populate `LocationCaption`.
 - **Matrix**: `geo_uri` is parsed as a pin location; altitude is ignored and `LocationIsLive` is always false.