agent: Add websearch tool (#28621)

Staff only for now. We'll work on making this usable for non zed.dev
users later

Release Notes:

- N/A

---------

Co-authored-by: Antonio Scandurra <me@as-cii.com>
Co-authored-by: Danilo Leal <daniloleal09@gmail.com>
Co-authored-by: Marshall Bowers <git@maxdeviant.com>

Cargo.lock

@@ -704,6 +704,7 @@ dependencies = [
  "assistant_tool",
  "chrono",
  "collections",
+ "feature_flags",
  "futures 0.3.31",
  "gpui",
  "html_to_markdown",
@@ -721,9 +722,11 @@ dependencies = [
  "ui",
  "unindent",
  "util",
+ "web_search",
  "workspace",
  "workspace-hack",
  "worktree",
+ "zed_llm_client",
 ]
 
 [[package]]
@@ -16609,6 +16612,36 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "web_search"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "collections",
+ "gpui",
+ "serde",
+ "workspace-hack",
+ "zed_llm_client",
+]
+
+[[package]]
+name = "web_search_providers"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "client",
+ "feature_flags",
+ "futures 0.3.31",
+ "gpui",
+ "http_client",
+ "language_model",
+ "serde",
+ "serde_json",
+ "web_search",
+ "workspace-hack",
+ "zed_llm_client",
+]
+
 [[package]]
 name = "webpki-root-certs"
 version = "0.26.8"
@@ -18287,6 +18320,8 @@ dependencies = [
  "uuid",
  "vim",
  "vim_mode_setting",
+ "web_search",
+ "web_search_providers",
  "welcome",
  "windows 0.61.1",
  "winresource",
@@ -18351,9 +18386,9 @@ dependencies = [
 
 [[package]]
 name = "zed_llm_client"
-version = "0.4.2"
+version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d28a5d6bdb0f40acf5261c39cabbf65a13b55ba4b86d9beb5b8b1c484373f1a"
+checksum = "57a5e1b5b3ace3fb55292a4c14036723bb8a01fac4aeaa3c2b63b51228412f94"
 dependencies = [
  "serde",
  "serde_json",