Regression on main: indexing table<string, V> gives unknown instead of V #1334

Repro

---@param pt table<string, integer>
---@param k string
local function g(pt, k)
  ---@type boolean
  local a = pt.X     -- 0.25.1: Cannot assign `integer` to `boolean`
  ---@type boolean
  local c = pt[k]    -- 0.25.1: Cannot assign `integer` to `boolean`
  local u = pt.X.y   -- 0.25.1: Undefined field `y`
  local v = pt.X()   -- 0.25.1: Cannot call expression of type `integer`
  return a, c, u, v
end

---@type integer
local i = 1
---@type boolean
local ctl = i        -- control: warns on both
return g, ctl

emmylua_check on 0.25.1 reports all four lines in g. On main (56267ead, 0.30.0) it reports only the control line. An index read of table<string, V> behaves as unknown: no assignment or argument mismatch, and indexing or calling it is allowed. It is the same for pt.X, pt['X'] and pt[k], for a parameter, and for a local typed with ---@type table<string, integer> (with or without an initializer).

Impact

Every table<string, V> read loses its type. With #1319 fixed, vim.env.X (---@type table<string, string?>) reads as unknown instead of string?.

Written with help from Claude Code.