continue first full balancing round

docs/content_design.md

@@ -455,14 +455,21 @@ verifies it empirically. Change the anchors first, re-derive stats second.
   survivability, range, no losses-to-attrition of own DPS) is worth
   paying for, so bigger guns get less raw DPS per threat.
 - **Hull HP = 15 per threat of hull contribution** (incl. ship base
-  time): drone 60, frigate 300, destroyer 550, cruiser 1500,
-  battlecruiser 2700, battleship 7500, dreadnought/carrier 15500.
-- **Armor HP ≈ 31 per threat** — a strong premium over hull HP (15)
+  time) as the *prior*; per-hull HP is the empirical trim knob for
+  arena results (guns are shared across many hulls, so gun changes move
+  many matchups at once — hull HP moves exactly one). Current values
+  after round-4 trims: drone 60, frigate 300, destroyer 550,
+  cruiser 1500, battlecruiser 2200, battleship 6300,
+  dreadnought/carrier 24000. (The capital hulls sit well above the
+  15/threat prior while their guns sit below the DPS prior — the arena
+  consistently prices big ships as tanks with taxed guns.)
+- **Armor HP ≈ 37 per threat** — a strong premium over hull HP (15)
   because armor is pure HP with no capability, and fights snowball:
   killing enemies removes their DPS, while surviving merely delays —
   so a point of HP must be cheaper than a point of DPS.
-  armor_plates adds 1000 HP at 32 threat (arena round 1: at 640 the
-  all-guns destroyer beat the armored one).
+  armor_plates adds 1200 HP at 32 threat (raised from 640 → 1000 →
+  1200: the all-guns destroyer beat the armored one in three
+  consecutive arena rounds).
 - **TTK check:** a mirror cruiser duel (51 DPS vs 2140 EHP) lasts ~42 s —
   inside the 30–60 s parity-fight band implied by the 25-ship fleet
   target. Capital mirrors run longer (~90 s), deliberately.
@@ -482,7 +489,10 @@ verifies it empirically. Change the anchors first, re-derive stats second.
 - **Weapon modifiers are capital economy:** ×1.2 damage at 22.5 threat
   beats adding a gun once a ship carries more than ~68 threat of weapons
   — so modifiers pay off on gun-heavy big hulls and are a waste on small
-  ones. Kept at ×1.2/×1.2/(×1.5 range, ×0.8 rate) deliberately.
+  ones. Damage/rate kept at ×1.2; the stabilizer's range multiplier was
+  cut ×1.5 → ×1.3 after round 2 — range is the strongest stat in the
+  orbit-AI's hands (free approach fire), and the stabilized battleship
+  was the one loadout still overperforming.
 - **Stations:** a fresh player station (3000 HP, 25 dmg × 1 Hz,
   range 120) holds one early parity wave unaided; the enemy station at
   level 0 matches it exactly and scales per push level
@@ -507,6 +517,54 @@ DPS (17→14, 70→52 damage), armor 640→1000, repair 25→12, station range
 still win flawlessly in round 2, the range ladder (kiting) is the next
 suspect, ahead of further DPS cuts.
 
+**Arena round 4 results (2026-07-04) and convergence policy:** mirrors
+at 0–3%; swarm vs cruisers +7%; glass vs armored resolved at +3% for
+armored (armor 1200 confirmed after four rounds of signal). Noise
+floor established: the battleship held +23% straight through a −10%
+EHP cut, and repair drifted 14→24% with no repair changes — single-run
+margins move ~±10% on a re-roll. Policy from here: only act on signals
+that persist two rounds; treat anything inside ±20% as converged for
+v1 (real-game playtests refine further). Armor-coupling overshoots
+corrected in round 5: battlecruiser 2000→2200, dreadnought/carrier
+22500→24000 (two-round persistent deficit vs destroyers). **Accepted,
+not chased:** the stabilized battleship beats a pure frigate fleet by
+~23% — the edge survived a stat cut, so it is mechanical (range), and
+"the extreme smallest-ship fleet modestly loses to a range-fitted
+capital" is desirable doctrine texture; the fair anti-capital answer
+is the mixed fleet, whose arena is balanced.
+
+**Arena round 3 results (2026-07-04, narrow lanes):** arenas were
+narrowed (height 10) so fleets can no longer pass each other — arena
+geometry is part of the fixture from here on; margins are only
+comparable within the same geometry. Results: mirrors healthy (1–7%);
+dreadnought closed to −11%; battleship improved to +22% (still over);
+drone swarm now beats cruisers by 14% (full engagement in the narrow
+lane favors numbers); mixed vs battlecruisers +18%; glass beat armored
+for the third consecutive round (+12%); repair 14%, two-to-one 78%,
+station set cracked at 51% by the 3× swarm (geometry changed under the
+stations — watch before touching stats). Round-4 knob changes:
+armor_plates 1000→1200 (the persistent glass signal; also lifts the
+armor-carrying cruiser/BC/destroyer/DN loadouts), battlecruiser hull
+2500→2000 (net −300 EHP after its armor gain), battleship 7000→6300
+(no armor in its loadout, clean −10%), dreadnought/carrier
+19000→22500 (the opposing destroyers gain armor too, so the DN needs
+the larger step).
+
+**Arena round 2 results (2026-07-04, with EHP-margin logging):** the
+mirror "bias" was noise — repeated runs split randomly, and winners
+finish at 5–7% EHP (near-mutual annihilation, healthy). Drones vs
+cruisers 10% and mixed vs battlecruisers 14% — near parity. The two
+capital fights diverged: battleship beat frigates at +33% while the
+dreadnought lost to destroyers at −37% — same guns, so the difference
+is the destroyers carrying the buffed armor plus the battleship's
+stabilizer putting all its guns at 75–150 m against 50 m opponents.
+Glass vs armored narrowed to 11% (watch; if it persists, armor
+1000→1200). Repair escort 11% — fair. Two-to-one decisive at 80%;
+station assault cracked by the 3× swarm at 13% (stations strong but
+breakable). Round-3 knob changes: stabilizer range ×1.5→×1.3, and
+per-hull HP trims — battlecruiser 2700→2500, battleship 7500→7000,
+dreadnought/carrier 15500→19000.
+
 ## Balancing targets (first pass, July 2026)
 
 The six root numbers for the balancing pass. Every derived value (threat