feat(render): #85 engine sprite-render system + deprecate bare draw_sprite

The engine already auto-ticks SpriteAnim/Motion; it now auto-DRAWS too.
Declare a Sprite component (id/offx/offy/scale/flip/tint/hidden, shipped from
ludic.core) on an entity with a Position and esys_sprite draws it each Render
frame — no hand-written Render handler, no hand animation (adds the SpriteAnim
frame when present). Registered on the engine-system registry (Render) and
spliced only when the game declares Sprite, so a game that never declares it
compiles byte-identically; opt out by omitting Sprite or `disable system
esys_sprite`.

Deprecates the bare draw_sprite/draw_sprite_scaled globals in favour of
Screen.sprite/Screen.sprite_scaled: a direct bare call emits a one-time
compile-time deprecation note (the bare form still lowers, since Screen.sprite
uses it); migrates the chronorift demo to the namespaced calls (golden render
byte-identical).

Example sprite_render (pixel-readback: engine draws the sprite, respects
hidden). Full suite 109/0, goldens byte-identical, fixpoint holds.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

runtime/native/image.ludic

@@ -367,6 +367,32 @@ function rt_draw_sprite_scaled(id: int, px: int, py: int, sc: int) -> void {
   }
 }
 
+# The full sprite blit the engine sprite-render system (#85) uses: an integer
+# scale (>= 1), a horizontal flip, and an optional solid tint (0 = keep the
+# sprite's own colours; non-zero = draw every opaque pixel in the tint colour, for
+# a hit-flash / team-colour silhouette). It funnels through the same put_px /
+# fill_rect chokepoints, so camera / zoom / clip / blend all apply.
+function rt_draw_sprite_ex(id: int, px: int, py: int, sc: int, flip: int, tint: int) -> void {
+  if id < 0 { return }
+  if id >= spr_n { return }
+  var s = sc
+  if s < 1 { s = 1 }
+  let base = id * SPR_SZ * SPR_SZ
+  for y in 0 .. SPR_SZ {
+    for x in 0 .. SPR_SZ {
+      var rx = x
+      if flip != 0 { rx = SPR_SZ - 1 - x }              # sample mirrored, draw upright
+      let p = spr_px[base + y * SPR_SZ + rx]
+      if ((p >> 24) & 255) != 0 {
+        var col = (p & 16777215)
+        if tint != 0 { col = (tint & 16777215) }
+        if s == 1 { rt_put_px(px + x, py + y, col) }
+        else { rt_fill_rect(px + x * s, py + y * s, s, s, col) }
+      }
+    }
+  }
+}
+
 # ---- .lspr sprite sheets (palette + ASCII rows) ---------------------------
 function rt_hexval(c: int) -> int {
   if c >= 48 { if c <= 57 { return c - 48 } }