feat(ui): number and key fields, notes, anchored popovers, text-shadow, and pictures as painted

- <input type="number" min max step>: typed digits replace its value (a minus when min allows one,
  a point when step has a fraction), Enter or leaving the field commits them held between min and
  max, the left and right arrows step it.
- <input type="key">: Enter or a click starts it listening and the next key is its value, Tab, the
  arrows and Enter included; Esc stops it listening, Backspace clears it, `shown` names the value,
  and ui_capturing() tells the host to leave its keys alone (through the frame that ended it).
- note="..." under any control's label (.ui-labels > .ui-label + .ui-note); a range's (or number's)
  value with decimals, format="percent" and a unit.
- A popover with `anchor="id"` (the nearest element of that id) or a bare `anchor` (the element
  before it) sits beside it by `placement` (right, left, bottom, top), its margin the gap, opens to
  the other side where it would leave the screen, and is kept on it.
- A tooltip's title splits into lines at a newline or a written \n.
- text-shadow, inherited, drawn sharp under the text.
- ui_opacity(): the group opacity a native's draw is at.
- border-image is drawn as painted with no background colour, tinted by one, and not at all when
  that colour is transparent (it drew a white nine-slice).
- A picture file is drawn untinted, as a browser draws one; an atlas cell (prefix:name) still takes
  the color around it, and an <img> with its own color is tinted by it.
- The render3d backend loads a picture again when its file changes or appears (a failed load was
  kept for ever), and at once after ui_image_reload(path); takes a path with a drive letter (C:/...)
  as a path rather than an atlas; and slices a nine-slice by its texture's own width and height.
- ui_inputs.ludic and ui_look.ludic; LANGUAGE.md and the changeset say all of it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/ludic.ui/controls.ludic

@@ -1,8 +1,7 @@
 # controls.ludic - what a control does: a button (or anything with on-click) is pressed, a checkbox
 # flips, a radio chooses its value, a select steps through its options, a range moves by its step
-# (or to where the pointer is on its track), a text field takes what is typed, a key field the next
-# key. Each says so with on-change and event.value, after the frame is drawn.
-var ct_capture: string = ""
+# (or to where the pointer is on its track), a text field takes what is typed, a number field its
+# digits, a key field the next key. Each says so with on-change and event.value, after the frame is drawn.
 function ct_type(n: UiNode) -> string {
   if n.tag == "select" { return "select" }
   if n.tag != "input" { return "" }
@@ -10,7 +9,7 @@ function ct_type(n: UiNode) -> string {
   if t == "" { return "text" }
   return t
 }
-function ct_takes_arrows(n: UiNode) -> bool { return ct_type(n) == "range" or ct_type(n) == "select" }
+function ct_takes_arrows(n: UiNode) -> bool { return ct_type(n) == "range" or ct_type(n) == "select" or ct_type(n) == "number" }
 function ct_takes_space(n: UiNode) -> bool { return ct_type(n) == "text" }
 function ct_change(n: UiNode, v: Val) -> void {
   ui_sound(ct_sound(n))
@@ -24,7 +23,7 @@ function ct_sound(n: UiNode) -> string {
 function ct_activate(n: UiNode) -> void {
   if not n.enabled { return }
   let t = ct_type(n)
-  if t == "checkbox" { ct_change(n, vl_bool(not ui_attr_on(n, "checked"))) } else if t == "radio" { ct_change(n, ui_attr(n, "value")) } else if t == "select" { ct_step(n, 1) } else if t == "key" { ct_capture = n.key } else if t == "" {
+  if t == "checkbox" { ct_change(n, vl_bool(not ui_attr_on(n, "checked"))) } else if t == "radio" { ct_change(n, ui_attr(n, "value")) } else if t == "select" { ct_step(n, 1) } else if t == "key" { ct_key_start(n) } else if t == "number" { ct_num_commit(n) } else if t == "" {
     ui_sound(ct_sound(n))
     ui_fire(n, "press", Value.null())
   }
@@ -36,6 +35,7 @@ function ct_step(n: UiNode, d: int) -> void {
     let ov = ui_attr(n.opts[at], "value")
     if Value.kind(ov) == 0 { ct_change(n, Value.int(at)) } else { ct_change(n, ov) }
   }
+  if t == "number" { ct_num_step(n, d) }
   if t == "range" {
     var step = Value.as_float(ui_attr(n, "step"))
     if step <= 0.0 { step = 1.0 }
@@ -70,11 +70,8 @@ function ct_drag(root: UiNode, key: string, x: float, y: float) -> void {
 # typing into a focused text field, or the key a key field is waiting for
 function ct_typed(n: UiNode) -> void {
   let t = ct_type(n)
-  if t == "key" and ct_capture == n.key and in_now.key != 0 and not in_now.enter {
-    ct_capture = ""
-    ct_change(n, Value.int(in_now.key))
-    return
-  }
+  if t == "key" { ct_key_typed(n) }
+  if t == "number" { ct_num_typed(n) }
   if t != "text" or (in_now.typed == "" and not in_now.backspace) { return }
   var s = ui_attr_text(n, "value")
   if in_now.backspace and len(s) > 0 { s = s[0..ct_char_start(s)] }