[Bug] Ultra plan generation irrelevant across multi-session blended context

Bug Description
Ultra plan across two different sessions, blended context, and the plan wasn't relevant to the project I was working on.

Environment Info

• Platform: darwin
• Terminal: ghostty
• Version: 2.1.101
• Feedback ID: 1dda3567-2e40-446e-82f8-eb1cc569d9e6

Errors

[{"error":"Error: Plugin MCP server error - generic-error: Missing required user configuration value: api_url. This should have been validated before variable substitution.\n    at TH6 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1817:34078)","timestamp":"2026-04-10T22:55:04.126Z"},{"error":"Error: Plugin MCP server error - generic-error: Missing required user configuration value: api_url. This should have been validated before variable substitution.\n    at TH6 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1817:34078)\n    at async G (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:6265:10566)","timestamp":"2026-04-10T22:55:05.749Z"},{"error":"Error: Plugin MCP server error - generic-error: Missing required user configuration value: api_url. This should have been validated before variable substitution.\n    at TH6 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1817:34078)\n    at async T (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:6265:11336)","timestamp":"2026-04-10T22:55:05.749Z"}]