Port timing/parity fixes, seamless battle transitions, faithful-res lock, and zoom-aware UI anchoring

Ports from a downstream fork, hand-surgered hunk-by-hunk to exclude the
fork's randomizer/pokescript work and to skip a FixedStep jitter-tolerance
attempt that never fixed the stutter it targeted.

- src/core/Timing.lua: hardware-accurate frame-delay catalog ported from
  pret/pokered, feeding BattleState:waitNext, EffectRegistry's miss/crit
  beats, TextBox/ChoiceBox scroll and prompt holds, and the battle
  silhouette slide/shake/blink/faint timings.
- Seamless battle transitions: Renderer:drawBattleWipe replaces the old
  160x144-only cascade with one wipe drawn over the whole surface at any
  zoom or window size; BattleTransition's per-style frame lengths are
  corrected against pokered-c's derivation; Transition.battleReturn adds
  the post-battle GBFadeInFromWhite the port never had.
- BATTLE SIZE / BATTLE BG options (BattleState:wantsFillScale/bgMode,
  Game.fillScaleInStack/worldBgBattleDim): battle surface can fill the
  window instead of the fixed integer letterbox, and the area around it
  can show white/black/the dimmed overworld instead of only white.
- src/core/FaithfulRes.lua: locks the window to an exact 160x144 multiple.
- Zoom-aware UI anchoring: Renderer:uiScale steps the UI down with survey
  zoom (gated to worldActive so the title/intro never shrink);
  Renderer:setUIAnchor lets TextBox, ChoiceBox, and an opted-in Menu
  (the START menu) pin themselves to a screen edge instead of the
  zoomed-out letterbox.

src/render/TextBox.lua

@@ -8,6 +8,7 @@
 
 local Font = require("src.render.Font")
 local Theme = require("src.ui.Theme")
+local Timing = require("src.core.Timing")
 
 local TextBox = {}
 TextBox.__index = TextBox
@@ -177,6 +178,13 @@ end
 function TextBox:update(dt)
   local input = self.game.input
   self.blink = (self.blink + 1) % 60
+  -- A page or CONT advance blocks the whole box while the original's scroll
+  -- and clear run (src/core/Timing.lua TEXT_SCROLL_PAIR / TEXT_PAGE_CLEAR).
+  -- Nothing types and no input is read until it drains.
+  if (self.holdFrames or 0) > 0 then
+    self.holdFrames = self.holdFrames - 1
+    return
+  end
   if self.done then
     if self.auto then
       if not self.autoStarted then
@@ -244,6 +252,13 @@ function TextBox:update(dt)
     return
   end
   if self.waiting then
+    -- _ContText and Paragraph both print the â–¼ and run ProtectedDelay3
+    -- before ManualTextScroll starts watching the joypad (home/text.asm:265,
+    -- :234), so the arrow is up for three frames that swallow the button.
+    if (self.preWait or 0) > 0 then
+      self.preWait = self.preWait - 1
+      return
+    end
     if input:wasPressed("a") or input:wasPressed("b") then
       require("src.core.Sound").play(self.game.data, "Press_AB")
       self.waiting = false
@@ -252,11 +267,17 @@ function TextBox:update(dt)
         self.contAdvance = false
         self.lineIndex = self.lineIndex + 1
         self:beginLine()
+        -- ScrollTextUpOneLine is 5 blocking frames and, as its own comment
+        -- says, is "always called twice in a row" (home/text.asm:280-305)
+        self.holdFrames = Timing.TEXT_SCROLL_PAIR
       else
         self.shown = {}
         self.pageIndex = self.pageIndex + 1
         self.lineIndex = 1
         self:beginLine()
+        -- ClearScreenArea then DelayFrames 20: the box sits empty before the
+        -- next page starts typing (home/text.asm:236-240)
+        self.holdFrames = Timing.TEXT_PAGE_CLEAR
       end
     end
     return
@@ -283,6 +304,7 @@ function TextBox:update(dt)
         if conts and conts[nextIdx] then
           -- pokered <CONT>: ▼ + WaitForTextScrollButtonPress before scroll
           self.waiting = true
+          self.preWait = Timing.TEXT_PRE_ADVANCE
           self.contAdvance = true
         else
           self.lineIndex = nextIdx
@@ -290,6 +312,7 @@ function TextBox:update(dt)
         end
       elseif self.pageIndex < #self.pages then
         self.waiting = true
+        self.preWait = Timing.TEXT_PRE_ADVANCE
         self.contAdvance = false
       else
         self.done = true
@@ -300,6 +323,15 @@ function TextBox:update(dt)
 end
 
 function TextBox:draw()
+  -- The dialogue box belongs against the bottom of the screen, not floating
+  -- in the middle of a zoomed-out letterbox.  Declared per frame; the
+  -- renderer blits this region to the screen edge and the rest of the UI
+  -- where it always was (Renderer:setUIAnchor).
+  local r = self.game and self.game.renderer
+  if r and r.setUIAnchor then
+    r:setUIAnchor(self.boxTx * 8, self.boxTy * 8,
+                  self.boxTw * 8, self.boxTh * 8, "bottom")
+  end
   Font.drawBox(self.boxTx, self.boxTy, self.boxTw, self.boxTh)
   love.graphics.setColor(0, 0, 0, 1)
   if self.scrollPx and self.scrollPx > 0 then