Antigravity Config Hardening & Cleanup

Context During the development of Epic #10186 (Concurrency Audit), we identified that the Twin Language Server bug is amplified by workspace-local .gemini/settings.json files conflicting with the global ~/.gemini/antigravity/mcp_config.json.

The Problem If an agent accidentally modifies or commits .gemini/settings.json, it can trigger dual-language server initialization in Antigravity, leading to 2x process duplication for MCP servers. Furthermore, stale files like rescueMigration.mjs clutter the operational environment.

The Architectural Reality Antigravity parses the MCP config twice if both a system-scope and workspace-scope config exist. The codebase should provide a template rather than an active configuration file by default.

The Fix

1. Rename .gemini/settings.json to .gemini/settings.template.json to prevent automatic parsing.
2. Update the Antigravity configuration paths referenced in learn/agentos/tooling/MemoryCoreMcpAuth.md.
3. Delete the obsolete rescueMigration.mjs file.

Acceptance Criteria

• .gemini/settings.json is renamed to a template file.
• Documentation reflects the correct configuration path for Antigravity's global config.
• rescueMigration.mjs is removed from the repository.

Out of Scope

• Fixes to the Antigravity Twin Language Server logic itself (this is a codebase hygiene layer).

Retrieval Hint: antigravity config hardening twin language server settings.template