docgen id is ambiguous

The way docgen currently calculates the id is ambiguous if

• a type and a value in the same module have the same name
• a module type and a module in the same module have the same name

This defeats the purpose of having a (supposedly unique) id.

Value / Type Example

type x = int
let x = 42

generates

{
  "name": "Example",
  "docstrings": [],
  "source": {
    "filepath": "src/Example.res",
    "line": 1,
    "col": 1
  },
  "items": [
  {
    "id": "Example.x",   <-- here
    "kind": "type",
    "name": "x",
    "signature": "type x = int",
    "docstrings": [],
    "source": {
      "filepath": "src/Example.res",
      "line": 1,
      "col": 1
    }
  }, 
  {
    "id": "Example.x",    <-- here
    "kind": "value",
    "name": "x",
    "signature": "let x: int",
    "docstrings": [],
    "source": {
      "filepath": "src/Example.res",
      "line": 2,
      "col": 5
    }
  }]
}

Module (Type) Example

// Example.res
module type M = { type x = int}
module M = {
  let x = 42
}

generates

{
  "name": "Example",
  "docstrings": [],
  "source": {
    "filepath": "src/Example.res",
    "line": 1,
    "col": 1
  },
  "items": [
  {
    "id": "Example.M",  <-- here #1
    "name": "M",
    "kind": "moduleType",
    "docstrings": [],
    "source": {
      "filepath": "src/Example.res",
      "line": 6,
      "col": 13
    },
    "items": [
    {
      "id": "Example.M.x",  <-- here #2
      "kind": "type",
      "name": "x",
      "signature": "type x = int",
      "docstrings": [],
      "source": {
        "filepath": "src/Example.res",
        "line": 6,
        "col": 19
      }
    }]
  }, 
  {
    "id": "Example.M",  <-- here #1
    "name": "M",
    "kind": "module",
    "docstrings": [],
    "source": {
      "filepath": "src/Example.res",
      "line": 7,
      "col": 8
    },
    "items": [
    {
      "id": "Example.M.x",  <-- here #2
      "kind": "value",
      "name": "x",
      "signature": "let x: int",
      "docstrings": [],
      "source": {
        "filepath": "src/Example.res",
        "line": 8,
        "col": 7
      }
    }]
  }]
}

Proposal

Either we state an id is only unique per kind which will probably confuse people, or we extend the id.
The simplest thing would probably be to additionaly include kind in the id: <kind>.<modulePath>.<itemName>.

For the above examples:

• type.Example.x / value.Example.x
• moduleType.Example.M / module.Example.M
• type.Example.M.x / value.Example.M.x

P.S: If above seems appropriate, I think I'd be able to send a PR to implement this:
I'd adapt the makeId function: https://github.com/rescript-lang/rescript-vscode/blob/a6108b369cf7bb6c69675dc090e96b64a5222ccf/tools/src/tools.ml#L301-L302
to take an additional optional labeled argument prefix and call it accordingly.

Start with the makeId function in tools/src/tools.ml at the linked location, then inspect its callers to understand how IDs are assembled for types, values, modules, and module types. Update the ID behavior only after checking those call sites; done means the example collisions produce distinct IDs across kinds and existing ID generation remains consistent.