Eliminate consecutive muscle overlap in all splits, cap rep ranges to 4-10

Splits:
- Removed SIDE_REAR_DELTS from Pull (rear delts get indirect row volume)
- Reordered Push/Pull x2 → Push/Legs/Pull/Legs to separate push and pull
- Replaced Upper/Lower/Legs/Upper/Lower → Upper/Lower/Push/Legs/Pull
- Reordered Bro split: Chest/Back/Arms/Shoulders/Legs (no triceps overlap)
- Removed ABS from Shoulders day, CALVES from Push/Pull hybrid days
- Redesigned 6-day hybrid to PPL + Arnold-style second half
- Added requires_rest_days flag for full-body splits (inherent overlap)
- Added validation function and test: no non-full-body split has overlap

Rep ranges:
- All tiers now 4-10: T1=4-6, T2=6-8, T3=8-10
- Female bias within same window: T1=5-8, T2=6-10, T3=8-10

https://claude.ai/code/session_01Lo7Z7GoRzG6hZkKwrxnXVk

Author: claude

ironforge/data/constants.py

@@ -29,18 +29,18 @@ class VolumeLandmarks:
 }
 
 
-# Rep ranges by tier
+# Rep ranges by tier — all capped to 4-10
 REP_RANGES: dict[Tier, tuple[int, int]] = {
-    Tier.T1: (6, 10),
-    Tier.T2: (8, 12),
-    Tier.T3: (12, 20),
+    Tier.T1: (4, 6),
+    Tier.T2: (6, 8),
+    Tier.T3: (8, 10),
 }
 
-# Female bias: shift rep ranges higher
+# Female bias: slightly higher within the 4-10 window
 REP_RANGES_FEMALE: dict[Tier, tuple[int, int]] = {
-    Tier.T1: (8, 12),
-    Tier.T2: (10, 15),
-    Tier.T3: (15, 25),
+    Tier.T1: (5, 8),
+    Tier.T2: (6, 10),
+    Tier.T3: (8, 10),
 }