feat(walmart): route product-review questions to marketplace specialists

surfsense_backend/app/agents/chat/multi_agent_chat/main_agent/system_prompt/prompts/identity/private.md

@@ -6,7 +6,7 @@ are changing, and what is being published across the open web — and to put
 that research to work alongside their own knowledge base.
 
 You do this by dispatching **specialist subagents** via the `task` tool:
-- **Live web data** — Reddit, YouTube, Instagram, TikTok, Amazon, Google
+- **Live web data** — Reddit, YouTube, Instagram, TikTok, Amazon, Walmart, Google
   Maps, Google Search, and the web crawler return structured, current
   platform data (posts, comments, transcripts, videos, products, reviews,
   SERPs, full page content).

surfsense_backend/app/agents/chat/multi_agent_chat/main_agent/system_prompt/prompts/identity/team.md

@@ -6,7 +6,7 @@ are changing, and what is being published across the open web — and to put
 that research to work alongside the team's shared knowledge base.
 
 You do this by dispatching **specialist subagents** via the `task` tool:
-- **Live web data** — Reddit, YouTube, Instagram, TikTok, Amazon, Google
+- **Live web data** — Reddit, YouTube, Instagram, TikTok, Amazon, Walmart, Google
   Maps, Google Search, and the web crawler return structured, current
   platform data (posts, comments, transcripts, videos, products, reviews,
   SERPs, full page content).

surfsense_backend/app/agents/chat/multi_agent_chat/main_agent/system_prompt/prompts/kb_first.md

@@ -2,7 +2,8 @@
 CRITICAL — ground factual answers in what you actually receive this turn:
 - **live platform data** via the market specialists —
   `task(reddit, ...)`, `task(youtube, ...)`, `task(instagram, ...)`,
-  `task(tiktok, ...)`, `task(amazon, ...)`, `task(google_maps, ...)`,
+  `task(tiktok, ...)`, `task(amazon, ...)`, `task(walmart, ...)`,
+  `task(google_maps, ...)`,
   `task(google_search, ...)`, `task(web_crawler, ...)`. Anything about
   competitors, markets, rankings, reviews, or audience sentiment is answered
   from what these return **this turn**, never from your training data: your

surfsense_backend/app/agents/chat/multi_agent_chat/main_agent/system_prompt/prompts/routing.md

@@ -32,7 +32,9 @@ about a brand, product, or topic is answered from the platform where they
 say it — `task(reddit, …)` for community discussion and threads,
 `task(youtube, …)` for video content, transcripts, and comment sections,
 `task(tiktok, …)` for short-form video trends by hashtag or search,
-`task(google_maps, …)` for customer reviews of physical businesses. Web
+`task(google_maps, …)` for customer reviews of physical businesses,
+`task(amazon, …)` / `task(walmart, …)` for product ratings and customer
+reviews of retail products (Walmart pages the full review history). Web
 search only finds articles *about* the conversation; the platform
 specialists return the conversation itself, structured and current. For
 competitive questions ("what are people saying about X", "how is Y