Add four-segment seasonal gradients

.context.json

@@ -95,33 +95,41 @@
   },
   "palettes": {
     "winter": {
-      "Z1_BG": 61,
+      "Z1_BG": 60,
+      "Z2_BG": 61,
+      "Z3_BG": 62,
+      "Z4_BG": 37,
       "Z1_FG": 255,
-      "Z2_BG": 37,
       "Z2_FG": 255,
       "PATH_FG": 194,
       "FRAME": 60
     },
     "spring": {
-      "Z1_BG": 71,
+      "Z1_BG": 70,
+      "Z2_BG": 71,
+      "Z3_BG": 72,
+      "Z4_BG": 120,
       "Z1_FG": 255,
-      "Z2_BG": 120,
       "Z2_FG": 22,
       "PATH_FG": 22,
       "FRAME": 65
     },
     "summer": {
-      "Z1_BG": 142,
+      "Z1_BG": 141,
+      "Z2_BG": 142,
+      "Z3_BG": 143,
+      "Z4_BG": 214,
       "Z1_FG": 255,
-      "Z2_BG": 214,
       "Z2_FG": 0,
       "PATH_FG": 232,
       "FRAME": 130
     },
     "autumn": {
-      "Z1_BG": 95,
+      "Z1_BG": 94,
+      "Z2_BG": 95,
+      "Z3_BG": 96,
+      "Z4_BG": 173,
       "Z1_FG": 255,
-      "Z2_BG": 173,
       "Z2_FG": 255,
       "PATH_FG": 223,
       "FRAME": 95
@@ -418,6 +426,7 @@
   "prompt_structure": {
     "zone1": "date time user",
     "zone2": "host path",
+    "seasonal_segments": "date | time | user | host+path (subtle seasonal gradient)",
     "line2": "status arrow + emoji",
     "emoji_padding": "Two spaces after the emoji before the cursor",
     "path_shortening": "Keeps /home/user or /Users/user visible and shortens middle if deep.",