Silver, ruby and diamond veins; treasury shows its treasures; announced payday

- New veins (appended kinds): silver (common), ruby (rare), diamond (very rare, far from the core);
  treasure caves contain gems; each treasure is worth a different amount per strike and per vein
- Imps carry one kind of treasure at a time
- Treasury tiles hold up to 500 each and show gold coins, silver bars, rubies or diamonds;
  spending empties random treasury tiles, the soul core keeps what does not fit
- Training no longer drains gold continuously: it is billed on the next payday
- Payday is announced 20 s before (message with the cost); the HUD shows a payday countdown and
  the cost of the next payday in red next to the gold counter
- Tests for the treasury and the payday bill

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

src/gfx.rs

@@ -6,7 +6,7 @@ use macroquad::prelude::*;
 
 pub const CELL: f32 = 16.0;
 const ATLAS_COLS: u32 = 16;
-const ATLAS_ROWS: u32 = 8;
+const ATLAS_ROWS: u32 = 9;
 
 // atlas indices (4 variants each)
 pub const T_ROCK: u32 = 0;
@@ -56,6 +56,12 @@ pub const T_FORTWALL: u32 = 108; // 4 variants: knight fortress masonry
 pub const D_SHARD: u32 = 112; // shard of the soul core
 pub const D_BANNER: u32 = 113; // knight banner
 pub const I_BRIDGE: u32 = 114;
+pub const T_SILVER: u32 = 115; // 2 variants each: veins in the earth
+pub const T_RUBY: u32 = 117;
+pub const T_DIAMOND: u32 = 119;
+pub const D_SILVER: u32 = 121; // treasury content
+pub const D_RUBY: u32 = 122;
+pub const D_DIAMOND: u32 = 123;
 
 pub struct Gfx {
     pub atlas: Texture2D,
@@ -643,6 +649,58 @@ fn gen_atlas() -> Image {
             None
         }
     });
+    // ---- more treasures: veins (earth with embedded pieces) and treasury piles
+    let vein = |x: i32, y: i32, v: u32, seed: u32, hi: Color, mid: Color, lo: Color, size: f32| -> Color {
+        let mut best = 99.0f32;
+        for k in 0..5 {
+            let nx = 2 + (hash(k, 1, v + seed) % 12) as i32;
+            let ny = 2 + (hash(k, 2, v + seed) % 12) as i32;
+            best = best.min((((x - nx).abs() + (y - ny).abs()) as f32) - if k % 2 == 0 { 0.5 } else { 0.0 });
+        }
+        if best < size * 0.4 {
+            hi
+        } else if best < size {
+            mid
+        } else if best < size + 0.8 {
+            lo
+        } else {
+            earth_px(x, y, v + seed)
+        }
+    };
+    for v in 0..2u32 {
+        cv.cell(T_SILVER + v, |x, y| Some(vein(x, y, v, 170, c(245, 245, 255), c(180, 186, 200), c(100, 104, 118), 2.0)));
+        cv.cell(T_RUBY + v, |x, y| Some(vein(x, y, v, 180, c(255, 150, 170), c(210, 30, 60), c(110, 16, 36), 1.6)));
+        cv.cell(T_DIAMOND + v, |x, y| Some(vein(x, y, v, 190, c(255, 255, 255), c(150, 230, 255), c(70, 140, 190), 1.4)));
+    }
+    // treasury heaps, same dome shape as the gold pile: silver bars, rubies, diamonds
+    let heap = |x: i32, y: i32| -> Option<f32> {
+        let dx = (x as f32 - 7.5) / 7.0;
+        let dy = (y as f32 - 11.0) / 5.0;
+        let d = dx * dx + dy * dy;
+        if d < 1.0 && y <= 14 {
+            Some(d)
+        } else {
+            None
+        }
+    };
+    cv.cell(D_SILVER, |x, y| {
+        let d = heap(x, y)?;
+        // bars: 4 px wide bricks in rows of 2
+        let row = y / 2;
+        let off = if row % 2 == 1 { 2 } else { 0 };
+        Some(if y % 2 == 0 { c(240, 242, 250) } else if (x + off) % 4 == 0 { c(110, 114, 128) } else if d > 0.6 { c(150, 156, 172) } else { c(196, 200, 216) })
+    });
+    let gems = |x: i32, y: i32, seed: u32, hi: Color, mid: Color, lo: Color| -> Option<Color> {
+        let d = heap(x, y)?;
+        // facetted stones: diamond shaped cells of 4 px
+        let (u, v) = (x + y, x - y + 16);
+        let (cu, cv) = (u / 4, v / 4);
+        let e = (u % 4 == 0) || (v % 4 == 0);
+        let h = hash(cu, cv, seed) % 3;
+        Some(if e { lo } else if h == 0 || (u % 4 == 1 && v % 4 == 1) { hi } else if d > 0.65 { lo } else { mid })
+    };
+    cv.cell(D_RUBY, |x, y| gems(x, y, 200, c(255, 150, 170), c(215, 30, 60), c(120, 12, 36)));
+    cv.cell(D_DIAMOND, |x, y| gems(x, y, 210, c(255, 255, 255), c(170, 232, 255), c(80, 150, 200)));
     cv.img
 }
 
@@ -1010,6 +1068,9 @@ impl Gfx {
             Kind::Earth if reinforced => T_REINF + v,
             Kind::Earth => T_EARTH + v,
             Kind::Gold => T_GOLD + v,
+            Kind::Silver => T_SILVER + (v & 1),
+            Kind::Ruby => T_RUBY + (v & 1),
+            Kind::Diamond => T_DIAMOND + (v & 1),
             Kind::Floor => {
                 if claimed {
                     T_CLAIM + v