fix(mcp, expand): pass projectRoot through expand/expand-all flows

Problem: expand_task & expand_all MCP tools failed with .env keys due to missing projectRoot propagation for API key resolution. Also fixed a ReferenceError: wasSilent is not defined in expandTaskDirect.

Solution: Modified core logic, direct functions, and MCP tools for expand-task and expand-all to correctly destructure projectRoot from arguments and pass it down through the context object to the AI service call (generateTextService). Fixed wasSilent scope in expandTaskDirect.

Verification: Tested expand_task successfully in MCP using .env keys. Reviewed expand_all flow for correct projectRoot propagation.

.taskmasterconfig

@@ -1,8 +1,8 @@
 {
   "models": {
     "main": {
-      "provider": "openai",
-      "modelId": "gpt-4o",
+      "provider": "anthropic",
+      "modelId": "claude-3-7-sonnet-20250219",
       "maxTokens": 100000,
       "temperature": 0.2
     },