feat(core): add web search tool and reasoning params (#11912)

Close [AI-60](https://linear.app/affine-design/issue/AI-60).

### What changed?
- Add Exa web search tool
- Add reasoning params

yarn.lock

@@ -961,6 +961,7 @@ __metadata:
     date-fns: "npm:^4.0.0"
     dotenv: "npm:^16.4.7"
     eventemitter2: "npm:^6.4.9"
+    exa-js: "npm:^1.6.13"
     express: "npm:^5.0.1"
     fast-xml-parser: "npm:^5.0.0"
     get-stream: "npm:^9.0.1"
@@ -19232,6 +19233,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"cross-fetch@npm:~4.1.0":
+  version: 4.1.0
+  resolution: "cross-fetch@npm:4.1.0"
+  dependencies:
+    node-fetch: "npm:^2.7.0"
+  checksum: 10/07624940607b64777d27ec9c668ddb6649e8c59ee0a5a10e63a51ce857e2bbb1294a45854a31c10eccb91b65909a5b199fcb0217339b44156f85900a7384f489
+  languageName: node
+  linkType: hard
+
 "cross-inspect@npm:1.0.1":
   version: 1.0.1
   resolution: "cross-inspect@npm:1.0.1"
@@ -20077,6 +20087,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"dotenv@npm:~16.4.7":
+  version: 16.4.7
+  resolution: "dotenv@npm:16.4.7"
+  checksum: 10/f13bfe97db88f0df4ec505eeffb8925ec51f2d56a3d0b6d916964d8b4af494e6fb1633ba5d09089b552e77ab2a25de58d70259b2c5ed45ec148221835fc99a0c
+  languageName: node
+  linkType: hard
+
 "ds-store@npm:^0.1.5":
   version: 0.1.6
   resolution: "ds-store@npm:0.1.6"
@@ -21191,6 +21208,16 @@ __metadata:
   languageName: node
   linkType: hard
 
+"exa-js@npm:^1.6.13":
+  version: 1.6.13
+  resolution: "exa-js@npm:1.6.13"
+  dependencies:
+    cross-fetch: "npm:~4.1.0"
+    dotenv: "npm:~16.4.7"
+  checksum: 10/17135b8d586032e8500f00c9b5f4e45cbe49ffb30a0ada77b42112ce71f5405bcdebfd8aed2edda175a5d0b15f57524836c825406cf07a8d71c14d37796056e1
+  languageName: node
+  linkType: hard
+
 "execa@npm:^1.0.0":
   version: 1.0.0
   resolution: "execa@npm:1.0.0"