migrate to the new for-loop syntax

Drop the ':' before captures (for xs (x) / for 0..n (i)); the index
capture becomes the trailing open range (for xs, 0.. (x, i)). 136
headers across 26 files, mechanical.

Five headless tests (banner_layout, hit_test, swipe_commit,
swipe_intent, swipe_reshuffle) also gain a direct
#import "modules/ui/types.sx" — they named Point/Frame through a
transitive import, which bare visibility no longer permits.

Gates: sx build --target ios-sim main.sx links; tools/run_tests.sh
23/23.

tests/easing.sx

@@ -51,7 +51,7 @@ main :: () -> s32 {
     p_io := ease_in_out_cubic(0.0);
     p_oc := ease_out_cubic(0.0);
     p_iq := ease_in_quad(0.0);
-    for 1..21: (i) {
+    for 1..21 (i) {
         t := cast(f32) i / 20.0;
         v_in := ease_in_cubic(t);     if v_in < p_in - 0.000001 { mono_in = false; } p_in = v_in;
         v_io := ease_in_out_cubic(t); if v_io < p_io - 0.000001 { mono_io = false; } p_io = v_io;
@@ -72,7 +72,7 @@ main :: () -> s32 {
     back_mx := ease_out_back(0.0); back_mn := ease_out_back(0.0);
     spr_mx  := spring(0.0);        spr_mn  := spring(0.0);
     spr_wobble := false;
-    for 1..21: (i) {
+    for 1..21 (i) {
         t := cast(f32) i / 20.0;
         b := ease_out_back(t);
         if b > back_mx { back_mx = b; }
@@ -98,7 +98,7 @@ main :: () -> s32 {
     //    squash (positive) and a stretch (negative) lobe, and stays bounded.
     print("== squash envelope bounded ==\n");
     sq_mx : f32 = 0.0; sq_mn : f32 = 0.0; sq_moves := false;
-    for 0..21: (i) {
+    for 0..21 (i) {
         t := cast(f32) i / 20.0;
         s := squash_envelope(t);
         if s > sq_mx { sq_mx = s; }
@@ -121,7 +121,7 @@ main :: () -> s32 {
     print("== illegal-swap bounce ==\n");
     bb_ends := bad_swap_bounce(0.0) == 0.0 and bad_swap_bounce(1.0) == 0.0;
     bb_mx : f32 = 0.0; bb_mx_t : f32 = 0.0; bb_mn : f32 = 0.0;
-    for 0..101: (i) {
+    for 0..101 (i) {
         t := cast(f32) i / 100.0;
         v := bad_swap_bounce(t);
         if v > bb_mx { bb_mx = v; bb_mx_t = t; }
@@ -151,18 +151,18 @@ main :: () -> s32 {
     //    starts later), the opposite of a flat lockstep row sharing one progress.
     print("== fall stagger bounded ==\n");
     stg_t0 := true; stg_t1 := true;
-    for 0..BOARD_COLS: (c) {
+    for 0..BOARD_COLS (c) {
         if fall_stagger_t(0.0, c) != 0.0 { stg_t0 = false; }
         if fall_stagger_t(1.0, c) != 1.0 { stg_t1 = false; }
     }
     stg_cascade := true;
-    for 1..BOARD_COLS: (c) {
+    for 1..BOARD_COLS (c) {
         if !(fall_stagger_t(0.5, c) < fall_stagger_t(0.5, c - 1)) { stg_cascade = false; }
     }
     stg_mono := true;
-    for 0..BOARD_COLS: (c) {
+    for 0..BOARD_COLS (c) {
         pp := fall_stagger_t(0.0, c);
-        for 1..21: (i) {
+        for 1..21 (i) {
             tt := cast(f32) i / 20.0;
             vv := fall_stagger_t(tt, c);
             if vv < pp - 0.000001 { stg_mono = false; }
@@ -190,14 +190,14 @@ main :: () -> s32 {
     lf_last  := approx(fall_landing_frac(BOARD_COLS - 1), 1.0);
     lf_mono := true;
     lf_seam := true;
-    for 0..BOARD_COLS: (c) {
+    for 0..BOARD_COLS (c) {
         if c >= 1 and !(fall_landing_frac(c) > fall_landing_frac(c - 1)) { lf_mono = false; }
         lf := fall_landing_frac(c);
         if !approx(fall_stagger_t(lf, c), 1.0) { lf_seam = false; }   // landed at lf
         if fall_stagger_t(lf - 0.05, c) >= 1.0 { lf_seam = false; }   // still in air just before
     }
     rlt_col_mono := true;
-    for 1..BOARD_COLS: (c) {
+    for 1..BOARD_COLS (c) {
         if !(round_land_time(0, c) > round_land_time(0, c - 1)) { rlt_col_mono = false; }
     }
     rlt_round_after := round_land_time(1, 0) > round_land_time(0, BOARD_COLS - 1);
@@ -222,22 +222,22 @@ main :: () -> s32 {
     //    gem 0..1 by diagonal across the round (lowest-diagonal = 0, the first to pop).
     print("== clear ripple bounded ==\n");
     rip_t0 := true; rip_t1 := true;
-    for 0..6: (j) {
+    for 0..6 (j) {
         u := cast(f32) j / 5.0;
         if clear_ripple_t(0.0, u) != 0.0 { rip_t0 = false; }
         if clear_ripple_t(1.0, u) != 1.0 { rip_t1 = false; }
     }
     rip_ripple := true;
-    for 1..6: (j) {
+    for 1..6 (j) {
         u := cast(f32) j / 5.0;
         up := cast(f32) (j - 1) / 5.0;
         if !(clear_ripple_t(0.5, u) < clear_ripple_t(0.5, up)) { rip_ripple = false; }
     }
     rip_mono := true;
-    for 0..6: (j) {
+    for 0..6 (j) {
         u := cast(f32) j / 5.0;
         pp := clear_ripple_t(0.0, u);
-        for 1..21: (i) {
+        for 1..21 (i) {
             tt := cast(f32) i / 20.0;
             vv := clear_ripple_t(tt, u);
             if vv < pp - 0.000001 { rip_mono = false; }
@@ -245,7 +245,7 @@ main :: () -> s32 {
         }
     }
     mm : MatchMask = ---;
-    for 0..BOARD_CELLS: (i) { mm.cells[i] = false; }
+    for 0..BOARD_CELLS (i) { mm.cells[i] = false; }
     mm.cells[Board.idx(5, 0)] = true;   // diagonal 5 — first to pop
     mm.cells[Board.idx(5, 1)] = true;   // diagonal 6
     mm.cells[Board.idx(5, 2)] = true;   // diagonal 7 — last to pop