refactor(core): remove autonomy dependency on tools layer

[cedric013]

Problem

core::tool_lifecycle constructs tools::autonomy::AutonomyState and calls tools::autonomy::should_auto_consolidate. This inverts the intended dependency direction: core depends on the MCP tools layer.

Proposed change

• Move AutonomyState, SearchHistory, and should_auto_consolidate into core::autonomy.
• Update core/server call sites to use the core module.
• Preserve a tools-layer re-export for compatibility.
• Add focused tests for consolidation interval, cooldown, and disabled state.

Acceptance criteria

• No core module references crate::tools::autonomy.
• Existing autonomy behavior remains unchanged.
• Rust formatting, clippy, and library tests pass.