Mapped types: field access and 'Type T not found' errors

[mmpestorich]

Problem

Mapped types like Pick<T, K> show errors and don't resolve fields correctly for direct access.

Reproduction

---@alias Pick<T, K extends keyof T> { [P in K]: T[P]; }

---@param v {name: string, age: number}
local function use_person(v)
  print(v.name)  -- Field access works inside function
  print(v.age)
end

---@type Pick<{name: string, age: number, email: string}, "name" | "age">
local picked

use_person(picked)  -- No error here (type compatibility works)

print(picked.name)  -- ERROR: Undefined field `name`

Observed Behavior

1. [type-not-found]Type 'T' not found error on the @alias Pick<T, K extends keyof T> line
2. [undefined-field]Undefined field 'name' when accessing picked.name directly
3. Type compatibility for function parameters appears to work (no error on use_person(picked))

Expected Behavior

1. No "Type T not found" error on the alias definition
2. Field access on mapped type variables should resolve correctly (e.g., picked.name should be string)

Environment

• emmylua_ls version: 0.19.0
• Editor: Neovim

Notes

The unit tests in generic_test.rs (test_type_mapped_pick, test_type_partial) only verify type compatibility via function parameters, not direct field access. This may explain why the feature appears to work in tests but not in practice.