Retune Iron Coast waves, enemy attacks and weapon presentation

mods/iron_coast_boss/README.md

@@ -1,17 +1,15 @@
 # Iron Coast Command Cruiser
 
-Independent version 1.0.0 enemy package for mod API 1. Enable/disable it from the in-game Mods screen and use it in any mission through `iron_coast_boss:unit`. Iron Coast mission 1 supplies placements and completion objectives; this package does not add a mission or override base content.
+API 1 package, version 1.0.1. Enable it in Mods at the main menu and apply the selection. This package has no mod dependencies.
 
-Airborne command cruiser enters at 2 pixels/tick, settles at y24 and patrols x80..144 indefinitely. It fires a fan of three 3 damage shells every 54 ticks. A standard pilot can destroy it with starter guns; it stays in their firing corridor.
+Enemy `iron_coast_boss:unit` is an airborne boss with **240** nominal health and a **84×56** logical canvas. Actual destruction awards 1,800 credits. The existing World rule halves boss health, rounded up, on Training and Rookie. SD and HD use the same logical body.
 
-Logical collision canvas `96×64`, top-left anchor `(0,0)`, health `160`, reward `1800` credits, firing interval `54` simulation ticks. The engine halves boss health on difficulties 0/1; difficulty 2/3 uses the declared health. SD mode uses `art/unit-sd.png`; enable HD art in Settings for `art/unit-hd.png`. The HD canvas is 8× logical resolution and bypasses automatic ScaleNx. Projectile artwork has an 8×8 logical canvas and an independent 64×64 HD version.
+Three-way fan / open-center gate / locked single shot. Each life has three health phases (above two-thirds, at/below two-thirds, at/below one-third of its actual spawn health). Every phase change restarts a full warning. Brief 8-pixel, 8-tick anchored charge arcs and existing quiet audio precede the salvo; the warning and short burst hold position, then the boss recovers into a bounded lateral patrol. Gun positions follow the existing artwork. No homing retarget occurs after aim is locked.
 
-The boss uses two registered frames (idle/amber charged); the scout and turret use stable single frames. All supplied variants stay on the same canvas and anchor. `art-qa.json` records transparency bounds and, for the boss, animation silhouette overlap.
+Warning leads are 18 / 16 / 14 / 12 ticks for Training / Rookie / Veteran / Elite. Recovery leaves a new approach opportunity; watch the charge cue and move into the opening before the volley.
 
-Enemy deaths increment the current mission objective `iron_coast_boss:defeated`. Persistent script `destroyed`, `hits` and `shots` counters are statistics; current-mission objectives reset when the mission restarts. Callbacks guard retired entities and use deterministic simulation data. No wall clock or unseeded random input enters the scripts.
+Only actual death increments `iron_coast_boss:defeated`; escape or time passing grants no objective credit. This enemy package does not decide mission completion. Its existing art, audio, generation provenance and asset recipes are retained.
 
-Generated PNG masters, SD/HD strips, previews and WAV sounds are included in Git. Original reference images under `art/source/` are excluded. Exact built-in imagegen prompts are in `prompts/`, with source IDs and generated-image provenance in `provenance.json`.
+## Validation and history
 
-To rebuild derived artwork from supplied generated masters and regenerate audio, install Pillow and run `python3 build_assets.py`. To regenerate only audio with the Python standard library, run `python3 build_assets.py --audio-only`. WAVs are original procedural mono 16-bit PCM at 22050 Hz; `audio-recipe.json` records deterministic seeds, sizes and hashes. The art pipeline resizes and assembles supplied images; it does not redraw them.
-
-Validate from the repository root: `cargo run -- --mods mods --validate-mods iron_coast_boss`. Synthetic behavior and save/replay tests: `cargo test --test enemies_mods`. Verify shipped artwork locally: `cargo test --test enemies_mods shipped_enemy_assets_are_valid_and_aligned`.
+See the [current Iron Coast retune results and limits](../../docs/iron-coast-retune.md). Package-local acceptance reports, validation results and retained test sources describe pre-retune 1.0 behavior unless a result explicitly identifies the newer package and runner. They remain historical material, not current playthrough guarantees.