Add Rain V0 for MeInput full-range chat analysis and delivery tooling.

Introduce rain-service orchestration, browser-safe chat skill filtering, MeInput
adapter helpers, and verify/deploy scripts so Rain mode can summarize recent input
without Memory V2 pollution.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/components/ChatPanel.tsx

@@ -1347,7 +1347,7 @@ export function ChatPanel({
               }}
             />
           )}
-          {onGrantedSkillsUpdate && (
+          {onGrantedSkillsUpdate && import.meta.env.VITE_HIDE_PAGE_TEMPLATES === '0' && (
             <button
               type="button"
               className="chat-template-shop-trigger"