Generic type inference breaks for class-style tables with indexed fields (---@class list<T>: { [integer]: T })

还没有人认领这个 Issue。

### How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

### Which OS are you using?

Windows

### What is the issue affecting?

Type Checking

### Expected Behaviour

```lua

---@type string[]
local testA = { }
local testB = { 1, 2, 3 }

local testAA = List(testA)
local testBB = List(testB)

local vAA1 = testAA[1] -- expected: string
local vBB1 = testBB[1] -- expected: integer

local vAA2 = testAA:at(1) -- expected: string
local vBB2 = testBB:at(1) -- expected: integer

---@type list
local testCC = List {}

-- newList -> expected: list
local newList = testCC:whereList(function(a) return a == 0 end)

-- front -> expected: number
local front = newList:front()
```

### Actual Behaviour

```lua
---@type string[]
local testA = { }
local testB = { 1, 2, 3 }

local testAA = List(testA)
local testBB = List(testB)

local vAA1 = testAA[1] -- actual: string|
local vBB1 = testBB[1] -- actual: string|

local vAA2 = testAA:at(1) -- actual: unknown
local vBB2 = testBB:at(1) -- actual: unknown

---@type list
local testCC = List {}

-- newList -> actual: list<>
local newList = testCC:whereList(function(a) return a == 0 end)

-- front -> actual: unknown
local front = newList:front()
```

### Reproduction steps

```lua
---@meta

---@generic T
---@param t T[]
---@return list
function List(t)
return listlib:new(t);
end

---@class list: { [integer] : T }
listlib = {}

---@generic T
---@param t T[]
---@return list
function listlib:new(t) end

---@generic T
---@param self list
---@param index integer
---@return T
function listlib:at(index) end

---@generic T
---@param self list
---@return T
function listlib:front() end

---@generic T
---@param self list
---@param predicate fun(a: T): boolean
---@return list
function listlib:whereList(predicate) end

---@type string[]
local testA = { }
local testB = { 1, 2, 3 }

local testAA = List(testA)
local testBB = List(testB)

local vAA1 = testAA[1] -- expected: string, actual: string|
local vBB1 = testBB[1] -- expected: integer, actual: string|

local vAA2 = testAA:at(1) -- expected: string, actual: unknown
local vBB2 = testBB:at(1) -- expected: integer, actual: unknown

---@type list
local testCC = List {}

-- newList -> expected: list, actual: list<>
-- front -> expected: number ,actual: unknown
local newList = testCC:whereList(function(a) return a == 0 end)
local front = newList:front()
```

### Additional Notes

_No response_

### Log File

_No response_

在 Visual Studio Code extension 中复现最小 Lua 示例，从通用的 List/listlib 声明和类风格的列表注解开始。跟踪 indexed access、at、whereList 和 front 的类型推断。完成的标准是推断出的类型与预期的 string、integer 和 number 结果相匹配，而不是 unknown 或未解析的泛型类型。

由索引模型根据 Issue 内容生成。