feat(agents): consolidate connectors under mcp_discovery; route web search through google_search

MCP consolidation:
- Route all MCP-capable connectors (Slack, Jira, Linear, ClickUp, Airtable,
  Notion, Confluence, interim Gmail/Calendar, custom MCP) through a single
  `mcp_discovery` subagent. Drive/OneDrive/Dropbox stay native to enrich the KB.
- Deprecate Discord/Teams/Luma: no viable official MCP server.

Google-only web search:
- Remove the main-agent `web_search` tool and the SearXNG platform service;
  all public web search now flows through the `google_search` subagent via task().
- Deprecate the Tavily/SearXNG/Linkup/Baidu search connectors (HTTP 410 on
  create, "Deprecated" badge); guide heavy users to the custom MCP connector.
- Remove web search from anonymous chat (pure Q&A).
- Tear SearXNG out of docker compose + install scripts; drop tavily-python
  and linkup-sdk deps and their config/env vars.

Fix:
- metrics._package_version() now swallows any metadata lookup failure. A
  malformed editable-install distribution with no `Version` field raised
  KeyError deep in importlib.metadata, and since it runs on every
  record_subagent_invoke_duration call it was crashing every task()
  delegation. Verified end-to-end against live GPT-5.4.

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

surfsense_web/components/free-chat/free-chat-page.tsx

@@ -117,7 +117,6 @@ export function FreeChatPage() {
 	const anonMode = useAnonymousMode();
 	const modelSlug = anonMode.isAnonymous ? anonMode.modelSlug : "";
 	const resetKey = anonMode.isAnonymous ? anonMode.resetKey : 0;
-	const webSearchEnabled = anonMode.isAnonymous ? anonMode.webSearchEnabled : true;
 
 	const [messages, setMessages] = useState<ThreadMessageLike[]>([]);
 	const [isRunning, setIsRunning] = useState(false);
@@ -173,7 +172,6 @@ export function FreeChatPage() {
 				model_slug: modelSlug,
 				messages: messageHistory,
 			};
-			if (!webSearchEnabled) reqBody.disabled_tools = ["web_search"];
 			if (turnstileToken) reqBody.turnstile_token = turnstileToken;
 
 			const response = await fetch(buildBackendUrl("/api/v1/public/anon-chat/stream"), {
@@ -323,7 +321,7 @@ export function FreeChatPage() {
 				throw err;
 			}
 		},
-		[modelSlug, tokenUsageStore, webSearchEnabled]
+		[modelSlug, tokenUsageStore]
 	);
 
 	const onNew = useCallback(

surfsense_web/components/free-chat/free-composer.tsx

@@ -1,13 +1,11 @@
 "use client";
 
 import { ComposerPrimitive, useAui, useAuiState } from "@assistant-ui/react";
-import { ArrowUpIcon, Globe, Paperclip, SquareIcon } from "lucide-react";
+import { ArrowUpIcon, Paperclip, SquareIcon } from "lucide-react";
 import { type FC, useCallback, useRef, useState } from "react";
 import { toast } from "sonner";
 import { TooltipIconButton } from "@/components/assistant-ui/tooltip-icon-button";
 import { Button } from "@/components/ui/button";
-import { Separator } from "@/components/ui/separator";
-import { Switch } from "@/components/ui/switch";
 import { Tooltip, TooltipContent, TooltipTrigger } from "@/components/ui/tooltip";
 import { useAnonymousMode } from "@/contexts/anonymous-mode";
 import { useLoginGate } from "@/contexts/login-gate";
@@ -76,8 +74,6 @@ export const FreeComposer: FC = () => {
 	const fileInputRef = useRef<HTMLInputElement>(null);
 
 	const hasUploadedDoc = anonMode.isAnonymous && anonMode.uploadedDoc !== null;
-	const webSearchEnabled = anonMode.isAnonymous ? anonMode.webSearchEnabled : true;
-	const setWebSearchEnabled = anonMode.isAnonymous ? anonMode.setWebSearchEnabled : () => {};
 
 	const handleTextChange = useCallback(
 		(e: React.ChangeEvent<HTMLTextAreaElement>) => {
@@ -208,26 +204,6 @@ export const FreeComposer: FC = () => {
 								: "Upload a document (text files only)"}
 						</TooltipContent>
 					</Tooltip>
-
-					<Separator orientation="vertical" className="h-4" />
-
-					<Tooltip>
-						<TooltipTrigger asChild>
-							<label
-								htmlFor="free-web-search-toggle"
-								className="flex cursor-pointer select-none items-center gap-1.5 rounded-md px-2 py-1 text-xs text-muted-foreground transition-colors hover:bg-accent hover:text-accent-foreground"
-							>
-								<Globe className="size-3.5" />
-								<span className="hidden sm:inline">Web</span>
-								<Switch
-									id="free-web-search-toggle"
-									checked={webSearchEnabled}
-									onCheckedChange={setWebSearchEnabled}
-								/>
-							</label>
-						</TooltipTrigger>
-						<TooltipContent>Toggle web search</TooltipContent>
-					</Tooltip>
 				</div>
 
 				<div className="flex min-w-0 items-center gap-1">