fix(rules): avoid the firing-into-melee penalty at 10 feet

SRD 'Attack - Shooting or Throwing into a Melee': a target at least 10 ft from the nearest friendly character lets you avoid the -4 penalty entirely (0, not -2). The -2 is reserved for targets two size categories larger than the engaged friendlies (0 at three+), which is not modeled (documented). Golden transcript unaffected (shot still misses).

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

tests/test_combat.py

@@ -816,7 +816,7 @@ def test_ranged_attack_ignores_flanking() -> None:
         "initiative: aly d20=9+0=9",
         "initiative: tgt d20=8+0=8",
         "round 1 tgt: AoO vs arc d20=15+2=17 AC 13 -> HIT 3 damage (6->3)",
-        "round 1 arc: short bow vs tgt d20=12+2-2(melee)=12 AC 15 -> MISS",
+        "round 1 arc: short bow vs tgt d20=12+2=14 AC 15 -> MISS",
         "round 1 aly: short sword vs tgt d20=10+0=10 AC 15 -> MISS",
         "round 1 tgt: short sword vs arc d20=5+2=7 AC 13 -> MISS",
         "battle over: draw after 1 rounds",