chore(mcp): upgrade zod to v4 to fix tsc OOM during build

Upgrades zod from ^3.24.3 to ^4.3.6 in the mcp package to resolve out-of-memory
errors during TypeScript compilation caused by @modelcontextprotocol/sdk's complex
Zod-derived types. Zod v4 has significantly simpler TypeScript generics, and also
satisfies the SDK's peer dependency requirement (^3.25 || ^4.0).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: brendan-kellam

packages/mcp/package.json

@@ -22,7 +22,7 @@
         "dedent": "^1.7.1",
         "escape-string-regexp": "^5.0.0",
         "express": "^5.1.0",
-        "zod": "^3.24.3"
+        "zod": "^4.3.6"
     },
     "bin": {
         "sourcebot-mcp": "./dist/index.js"

yarn.lock

@@ -8539,7 +8539,7 @@ __metadata:
     tsc-watch: "npm:6.2.1"
     tsx: "npm:^4.0.0"
     typescript: "npm:^5.0.0"
-    zod: "npm:^3.24.3"
+    zod: "npm:^4.3.6"
   bin:
     sourcebot-mcp: ./dist/index.js
   languageName: unknown
@@ -22252,14 +22252,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"zod@npm:^3.24.3":
-  version: 3.24.3
-  resolution: "zod@npm:3.24.3"
-  checksum: 10c0/ab0369810968d0329a1a141e9418e01e5c9c2a4905cbb7cb7f5a131d6e9487596e1400e21eeff24c4a8ee28dacfa5bd6103893765c055b7a98c2006a5a4fc68d
-  languageName: node
-  linkType: hard
-
-"zod@npm:^3.25 || ^4.0, zod@npm:^3.25.76 || ^4, zod@npm:^4.1.13":
+"zod@npm:^3.25 || ^4.0, zod@npm:^3.25.76 || ^4, zod@npm:^4.1.13, zod@npm:^4.3.6":
   version: 4.3.6
   resolution: "zod@npm:4.3.6"
   checksum: 10c0/860d25a81ab41d33aa25f8d0d07b091a04acb426e605f396227a796e9e800c44723ed96d0f53a512b57be3d1520f45bf69c0cb3b378a232a00787a2609625307