fix: keyboard KB_START_Y must match render position (70), simplify row 3 layout

- KB_START_Y was 310 but keyboard rendered at y=70 — touch hits never matched
- Row 3 simplified to 3 keys: [layer/shift, space, done]
- All 362 unit tests pass

4 files changed, 7 insertions, 10 deletions

diff --git a/main/display.c b/main/display.c
index 44af981..e5e31c4 100644
--- a/main/display.c
+++ b/main/display.c
@@ -454,7 +454,6 @@ static void render_wifi_setup_password(void) {
             } else if (c == '\004') {
                 label[0] = '>';
                 fg = COLOR_GREEN;
-                bg = COLOR_DARKGRAY;
             } else if (c == '\b') {
                 label[0] = '<';
                 bg = COLOR_GRAY;
diff --git a/main/keyboard.c b/main/keyboard.c
index 741bd08..33365de 100644
--- a/main/keyboard.c
+++ b/main/keyboard.c
@@ -5,21 +5,21 @@ static const char *s_alpha_lower[] = {
     "qwertyuiop",
     "asdfghjkl",
     "\001zxcvbnm\b",
-    "\002\003 \004"
+    "\002\003\004"
 };
 
 static const char *s_alpha_upper[] = {
     "QWERTYUIOP",
     "ASDFGHJKL",
     "\001ZXCVBNM\b",
-    "\002\003 \004"
+    "\002\003\004"
 };
 
 static const char *s_numsym[] = {
     "1234567890",
     "-/:;()$&@\"",
     "\001.,?!'\\b",
-    "\002\003 \004"
+    "\002\003\004"
 };
 
 #define CTRL_SHIFT  '\001'
@@ -73,9 +73,7 @@ static int key_width_at(int row, int col, int total_keys) {
     if (row == 3) {
         if (col == 0) return 42;
         if (col == total_keys - 1) return 50;
-        if (total_keys == 3 && col == 1) return 168;
-        if (total_keys == 4 && col == 1) return 168;
-        if (total_keys == 4 && col == 2) return 42;
+        return 168;
     }
     return KB_KEY_W;
 }
diff --git a/main/keyboard.h b/main/keyboard.h
index d7b3400..495c499 100644
--- a/main/keyboard.h
+++ b/main/keyboard.h
@@ -9,7 +9,7 @@
 #define KB_KEY_H         36
 #define KB_KEY_GAP       2
 #define KB_ROW_COUNT     4
-#define KB_START_Y       310
+#define KB_START_Y       70
 
 typedef enum {
     KB_ALPHA_LOWER,
diff --git a/tests/unit/test_keyboard.c b/tests/unit/test_keyboard.c
index 4cb923d..e069f28 100644
--- a/tests/unit/test_keyboard.c
+++ b/tests/unit/test_keyboard.c
@@ -38,10 +38,10 @@ int main(void)
     ASSERT_EQ_INT(0, count, "Invalid row 99 returns 0");
 
     {
-        kb_result_t r = kb_hit_test(160, 100, KB_ALPHA_LOWER);
+        kb_result_t r = kb_hit_test(160, 10, KB_ALPHA_LOWER);
         ASSERT(r.action == KB_ACTION_NONE, "Touch above keyboard = NONE");
 
-        r = kb_hit_test(160, 500, KB_ALPHA_LOWER);
+        r = kb_hit_test(160, KB_START_Y + KB_ROW_COUNT * (KB_KEY_H + KB_KEY_GAP) + 10, KB_ALPHA_LOWER);
         ASSERT(r.action == KB_ACTION_NONE, "Touch below keyboard = NONE");
     }