Function resolve_tool_paths 

pub fn resolve_tool_paths(
    args: &Map<String, Value>,
    ctx: &ToolContext,
) -> ResolvedPaths

Resolve tool paths with multi-root support.

Priority: 0. repo argument (multi-repo alias → specific root)

1. paths array argument (explicit multi-root)
2. path string argument (single root, pre-resolved by dispatch)
3. Session extra_roots (default multi-root from config/MCP)
4. Fallback to "." (project root)