Quest dialogs: stay centred, clickable, closable with Esc

- Quest dialogs are tooltips. A tooltip now keeps the offset it gets when it
  becomes visible (the hovered window's, or centred for dialogs) and records
  it for hit tests; its own event handler is shifted too. Hidden windows no
  longer count as hovered.
- Esc closes a visible dialog the way its answer buttons do: hide, then
  cDialogManager::Answer with no answer (ends the input lock, nothing chosen).
- Autotest can select a save game row (-Save).
- Names for the UI manager, tooltip and dialog functions.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/hud.md

@@ -70,3 +70,19 @@ clicks only hit at the unshifted position. `cUI_Button2`, `cUI_Static2`,
 `cUI_StaticText64`, `cUI_StaticText64FX` (render and event) and
 `cUI_TextLines` (render) are hooked as centred windows too; inside other
 windows they are in that window's scope already (outermost wins).
+
+## Tooltips and quest dialogs (2026-10-16)
+
+Quest dialogs are tooltips: `cUI_Manager::tooltipCreate` (`0x75a870`) hands
+out a panel from a pool at cUI_Manager +0x124 (`UI_WND_TOOLTIP`, created
+1024x768, flags 0x804 while hidden); the quest dialog used one at 136,306,
+752x157 (flags 0x805). Tooltips used to be drawn with the offset of the moved
+window under the cursor in every frame, and without recording an offset for
+hit tests: dialogs jumped to the 1024 frame when the cursor left the UI, and
+their clicks only hit at the unshifted position. Now a tooltip keeps the
+offset it gets when it becomes visible (the hovered window's, or the centre
+when no moved window is under the cursor: a dialog) and records it for hit
+tests. Visible dialog tooltips: `mods::hud::VisibleDialogTooltips`.
+
+The standalone control hooks (buttons, texts) above turned out not to be what
+the quest dialog is made of; they stay, for top-level controls in general.