docs(manual): both hosts read the hint ladder, placeholder is the attribute

The web section said the hintText key does not read the ladder on both
hosts and told authors to select such a field by attrs.hintText instead.
Both hosts read it now, so that instruction is gone rather than left
standing beside a newer sentence.

placeholder is stated as the attribute the markup writes and nothing
more, the tap path is stated as failing by name where no CSS says what
the ladder says, and the alias table gains the row it was missing.

docs/manual/spec-language.md

@@ -128,6 +128,7 @@ These key aliases are resolved automatically so selectors work across platforms
 | `testID` | `data-testid` |
 | `className` | `class` |
 | `elementType` | `class` |
+| `placeholderValue` | `hintText` |
 
 ## AccessibilityElement fields
 
@@ -184,12 +185,20 @@ Fields available on every element returned by `find` / `findAll`:
   answers to one, on either host.
 - `attrs.hintText` names an editable field the way a user reads it: its
   `aria-label`, the `<label>` bound to it, its `placeholder`, then its `name`.
-  The `hintText` selector key does not read that ladder on both hosts: the
+  The `hintText` and `placeholderValue` selector keys read that same ladder,
-  accessibility tree resolves it against the derived attribute above, and the
+  and both hosts derive it with the same function, so a field labelled by
-  web runtime resolves it against `placeholder` alone. A field labelled by
+  `aria-label` or by a bound `<label>` answers to `{hintText: "Email"}` here
-  `aria-label` or a bound `<label>` therefore answers to `{hintText: "Email"}`
+  the way it does on the accessibility tree. A rung the ladder passed over is
-  in one and not the other. Select such a field by `attrs.hintText` until the
+  not the field's hint, so a field whose `aria-label` outranks its
-  two agree.
+  `placeholder` answers to the label and not to the placeholder. A field with
+  no hint at all answers to neither key, never to `{hintText: ""}`.
+- `placeholder` is the attribute the markup writes and nothing more. It names
+  a field whose hint is something else, and it names nothing on Android or
+  iOS, neither of which writes an attribute by that name.
+- A `hintText` or `placeholderValue` target reaches the tap path only where the
+  hierarchy dump resolved it to no coordinates, and no CSS says what the ladder
+  says, so the step fails naming the selector rather than tapping whichever
+  field carries the value as a `placeholder`.
 
 ### KMP (Kotlin Multiplatform)