Combat stats pass: anchor-derived stats and canonical arena suite

Derive all combat stats from documented anchors (content_design.md,
'Combat stat anchors'): weapon DPS ~0.6 per threat with a mild size
discount traded for range (railgun m/l damage 17/70), hull HP at 15
per hull threat (drone 60 up to capitals 15500), armor at a 20/threat
premium (armor_plates 640 HP), repair at ~2 HP/s per threat (25 HP per
cycle), salvager range fixed to 60 m with cargo 20, and a monotone
mobility ladder (the placeholder drone was the least agile ship).
Stations anchored to 'a fresh station holds one early parity wave';
enemy level 0 matches the player station and scales per push. HQ 5000
HP. scrap_despawn_seconds 30 -> 120 so capital-sized scrap drops are
collectable.

Rewrite balancing.toml as the canonical 12-arena suite: class mirrors,
equal-threat cross-tier matchups with counts from the verified threat
values, a two-to-one decisiveness check, armored-vs-glass and
repair-escort doctrine matchups, and station assault. The carrier
arena is expected to lose until drone launching exists (hangar is dead
threat) - documented, not stat-compensated.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DyCu8vwChKMbLJQ3xosYEN

bin/app/data/config/stations.toml

@@ -1,10 +1,18 @@
+# stations.toml
+#
+# Combat-pass anchors (see docs/content_design.md, "Combat stat anchors"):
+# a fresh player defence station holds one early parity wave unaided; the
+# enemy station at level 0 matches the player station exactly and scales
+# with the push level x. Station scrap drops stay authored (pushing rewards
+# are tuned independently of ship production costs, REQ-RES-SCRAP-DROP).
+
 [hq]
 surface_mask = [
   "AAA",
   "AAA",
   "AAA",
 ]
-hp_formula = "1000"
+hp_formula = "5000"
 
 [player_station]
 surface_mask = [
@@ -12,19 +20,19 @@ surface_mask = [
   "SS",
 ]
 level = 1
-hp_formula = "300"
-damage_formula = "5"
+hp_formula = "3000"
+damage_formula = "25"
 range_m_formula = "200"
 fire_rate_hz_formula = "1"
-scrap_drop_formula = "10"
+scrap_drop_formula = "40"
 
 [enemy_station]
 surface_mask = [
   "SS",
   "SS",
 ]
-hp_formula = "300 + 150*x"
-damage_formula = "2 + 1*x"
+hp_formula = "3000 + 1500*x"
+damage_formula = "25 + 12*x"
 range_m_formula = "200"
-fire_rate_hz_formula = "1.0 + 0.2*x"
-scrap_drop_formula = "10 + 5*x"
+fire_rate_hz_formula = "1.0 + 0.1*x"
+scrap_drop_formula = "40 + 30*x"