feat(agent): add automatic web search and rename uploads dir to workspace

- Add WEB_SEARCH_ENABLED and WEB_SEARCH_MAX_RESULTS config options
- Detect search-intent messages via trigger keywords and inject web
  results into the AI context
- Instruct the system prompt to use web search for factual, current,
  or time-sensitive questions instead of inventing data
- Rename uploads directory from `uploadsfiles/` to `workspace/`,
  updating .gitignore and backup instructions in DEPLOY.md

.env

@@ -35,6 +35,10 @@ MAX_INTERVAL_MINUTES=90
 # Maximum conversation history length per context (messages)
 MAX_HISTORY_LENGTH=50
 
+# Enable automatic web search when needed
+WEB_SEARCH_ENABLED=true
+WEB_SEARCH_MAX_RESULTS=5
+
 # Upload file context max characters sent to AI (0 = no truncation)
 UPLOAD_CONTEXT_MAX_CHARS=0