ludic.ui: emit click reaches on-click, and a select's < steps back

From the user's play: clicking an item in the pack opened nothing, and the wardrobe's picks did
not respond - both are a component whose button says `emit click` (ItemCell, LookCell, ListRow),
answered by its user's on-click. An on-* attribute's name is kept as a browser would have it, so
on-click is on-press (tpl_event), and the emit looked for "click" and found nothing. An emitted
name now goes through the same tpl_event.

And a settings cycler's left arrow did the right one's job: any press let go on a select stepped it
forward. ct_activate_at steps back when it is let go over the select's .ui-prev; Enter and the rest
of the select still step forward.

Goldens ui_emit_click (the mouse and a press both reach on-click; with the toolchain before this,
neither does) and ui_select_arrows (1 -> 0 on <, then 2 on > >; before this, 1 -> 2 on <). The 33
ui examples pass.

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

examples/library/ui_emit_click.ludic

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+# ui_emit_click.ludic - a component whose button says `emit click` is answered by its user's
+# on-click, by the mouse or a press: on-click is kept as on-press, and the emit once looked for
+# "click" and found nothing (the pack's items and the wardrobe's picks did not respond)
+import "ludic.ui"
+import "ui_emit_click_parts/Cell.ludic"
+import "ui_emit_click_parts/Pick.ludic"
+program UiEmitClick {
+  numbers float
+  function frame(ui_st: mut UiState, x: float, y: float, down: bool) -> UiNode {
+    let i = new UiInput
+    i.x = x
+    i.y = y
+    i.down = down
+    ui_input(ui_st, i)
+    ui_show(ui_st, "Pick", null, 0.0, 0.0, 400.0, 400.0)
+    let root: UiNode = ui_nodes(ui_st, "Pick", null)
+    ui_place(ui_st, root, 0.0, 0.0, 400.0, 400.0)
+    return root
+  }
+  function first_text(n: UiNode) -> string {
+    if n.text != "" { return n.text }
+    for i in 0 .. len(n.children) { let t = first_text(n.children[i]); if t != "" { return t } }
+    return ""
+  }
+  entry (ui_st: mut UiState) {
+    var root = frame(ui_st, -1.0, -1.0, false)
+    root = frame(ui_st, -1.0, -1.0, false)
+    let b = root.children[0].children[2].children[0]
+    let x = b.x + b.cw / 2.0
+    let y = b.y + b.ch / 2.0
+    root = frame(ui_st, x, y, false)
+    root = frame(ui_st, x, y, true)
+    root = frame(ui_st, x, y, false)
+    root = frame(ui_st, x, y, false)
+    let clicked = first_text(root)
+    ui_press(ui_st, root.children[0].children[1].children[0])
+    root = frame(ui_st, x, y, false)
+    print(`{clicked} | pressed: {first_text(root)}`)
+  }
+}

examples/library/ui_emit_click_parts/Cell.lss

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+.cell { width: 100px; height: 40px }

examples/library/ui_emit_click_parts/Cell.ludic

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+component Cell {
+  prop caption: string = ""
+}

examples/library/ui_emit_click_parts/Cell.xml

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+<div class="item">
+  <button class="cell" on-click="emit click"><p>{caption}</p></button>
+</div>

examples/library/ui_emit_click_parts/Pick.lss

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+div { width: 400px }

examples/library/ui_emit_click_parts/Pick.ludic

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+component Pick {
+  state got: int = -1
+  on pick(i: int) { got = i }
+}

examples/library/ui_emit_click_parts/Pick.xml

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+<div>
+  <p>got {got}</p>
+  <Cell caption="a" on-click="pick(1)"/>
+  <Cell caption="b" on-click="pick(2)"/>
+</div>

examples/library/ui_select_arrows.ludic

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+# ui_select_arrows.ludic - a select is a cycler: a press let go on its < steps back and on its >
+# (or anywhere else on it, or Enter) forward. The < once stepped forward too.
+import "ludic.ui"
+program UiSelectArrows {
+  numbers float
+  state SelState { v: int = 1 }
+  view V (sel_st: mut SelState) {
+    v = sel_st.v
+    on set(x: int) { sel_st.v = x }
+  }
+  const PAGE: string = "<ui><screen name='s'><select label='Every' value='{v}' on-change='set(event.value)'><option value='{0}'>Off</option><option value='{1}'>5</option><option value='{2}'>15</option><option value='{3}'>30</option></select></screen></ui>"
+  function frame(ui_st: mut UiState, x: float, y: float, down: bool) -> UiNode {
+    let i = new UiInput
+    i.x = x
+    i.y = y
+    i.down = down
+    ui_input(ui_st, i)
+    ui_show(ui_st, "s", view_v(), 0.0, 0.0, 400.0, 400.0)
+    let root: UiNode = ui_nodes(ui_st, "s", view_v())
+    ui_place(ui_st, root, 0.0, 0.0, 400.0, 400.0)
+    return root
+  }
+  function part(n: UiNode, cls: string) -> UiNode {
+    for i in 0 .. len(n.children) {
+      if List.contains(n.children[i].classes, cls) { return n.children[i] }
+      let f = part(n.children[i], cls)
+      if f != null { return f }
+    }
+    return null
+  }
+  function click(ui_st: mut UiState, cls: string) -> void {
+    let root = frame(ui_st, -1.0, -1.0, false)
+    let p = part(root, cls)
+    let x = p.x + p.cw / 2.0
+    let y = p.y + p.ch / 2.0
+    frame(ui_st, x, y, false)
+    frame(ui_st, x, y, true)
+    frame(ui_st, x, y, false)
+    frame(ui_st, x, y, false)
+  }
+  entry (ui_st: mut UiState, sel_st: SelState) {
+    ui_backend(ui_st, new UiBackend)
+    ui_load_text(ui_st, PAGE, "s.xml")
+    frame(ui_st, -1.0, -1.0, false)
+    click(ui_st, "ui-prev")
+    let a = sel_st.v
+    click(ui_st, "ui-next")
+    click(ui_st, "ui-next")
+    print(`prev {a} next next {sel_st.v}`)
+  }
+}