rename render/ files to UpperCamelCase to match client convention

The render/ tree was the only place in the client still using kebab-case
filenames. Brings ~80 files in line with the rest of src/client/
(BuildPreviewController, TransformHandler, etc.). Directories kept as
they were (name-pass/, fx-pass/, passes/, utils/, debug/) since the
codebase already mixes those.

Two collisions surfaced and got resolved: render/types/ is a directory,
not a file, so its imports kept the lowercase form; and the sed pass
incidentally normalized core/pathfinding imports, which had to be
reverted since that file is actually lowercase on disk despite some
imports having referenced it as ./Types under macOS case-insensitive
resolution.

src/client/render/GameConstants.ts

@@ -0,0 +1,163 @@
+/**
+ * game-constants.ts — Upstream game facts replicated in the renderer/shim.
+ *
+ * All values here are sourced from upstream game code. When upstream changes,
+ * audit this file first.
+ *
+ * Primary sources:
+ *   - vendor/openfront/src/core/configuration/DefaultConfig.ts  (DefaultConfig, DefaultServerConfig)
+ *   - vendor/openfront/src/client/graphics/layers/FxLayer.ts    (visual-only constants)
+ */
+
+import {
+  UT_ATOM_BOMB,
+  UT_CITY,
+  UT_DEFENSE_POST,
+  UT_FACTORY,
+  UT_HYDROGEN_BOMB,
+  UT_MIRV_WARHEAD,
+  UT_MISSILE_SILO,
+  UT_PORT,
+  UT_SAM_LAUNCHER,
+} from "./types";
+
+// ---------------------------------------------------------------------------
+// Tick timing
+// ---------------------------------------------------------------------------
+
+/**
+ * Milliseconds per game tick.
+ * Source: DefaultServerConfig.turnIntervalMs() → return 100
+ */
+export const MS_PER_TICK = 100;
+
+// ---------------------------------------------------------------------------
+// Unit health
+// ---------------------------------------------------------------------------
+
+/**
+ * Maximum health for a Warship unit.
+ * Source: DefaultConfig.unitInfo(UnitType.Warship) → { maxHealth: 1000 }
+ */
+export const WARSHIP_MAX_HEALTH = 1000;
+
+// ---------------------------------------------------------------------------
+// Construction durations (ticks)
+// ---------------------------------------------------------------------------
+
+/**
+ * How many ticks each structure type takes to finish construction.
+ * Source: DefaultConfig.unitInfo(type).constructionDuration (non-instantBuild path):
+ *   case UnitType.City:        constructionDuration: 2 * 10
+ *   case UnitType.Port:        constructionDuration: 2 * 10
+ *   case UnitType.Factory:     constructionDuration: 2 * 10
+ *   case UnitType.DefensePost: constructionDuration: 5 * 10
+ *   case UnitType.MissileSilo: constructionDuration: 10 * 10
+ *   case UnitType.SAMLauncher: constructionDuration: 30 * 10
+ */
+export const CONSTRUCTION_DURATIONS: Readonly<Record<string, number>> = {
+  [UT_CITY]: 2 * 10,
+  [UT_PORT]: 2 * 10,
+  [UT_FACTORY]: 2 * 10,
+  [UT_DEFENSE_POST]: 5 * 10,
+  [UT_MISSILE_SILO]: 10 * 10,
+  [UT_SAM_LAUNCHER]: 30 * 10,
+};
+
+// ---------------------------------------------------------------------------
+// Missile cooldowns (ticks)
+// ---------------------------------------------------------------------------
+
+/**
+ * Ticks for a SAM Launcher to reload one missile.
+ * Source: DefaultConfig.SAMCooldown() → return 120
+ * NOTE: different from SiloCooldown — do not conflate.
+ */
+export const SAM_COOLDOWN_TICKS = 120;
+
+/**
+ * Ticks for a Missile Silo to reload one missile.
+ * Source: DefaultConfig.SiloCooldown() → return 75
+ */
+export const SILO_COOLDOWN_TICKS = 75;
+
+// ---------------------------------------------------------------------------
+// Deletion mark duration (ticks)
+// ---------------------------------------------------------------------------
+
+/**
+ * How many ticks a structure remains in the "marked for deletion" state.
+ * Source: DefaultConfig.deletionMarkDuration() → return 30 * 10
+ */
+export const DELETION_MARK_DURATION = 30 * 10;
+
+// ---------------------------------------------------------------------------
+// Nuke explosion visual radii (tiles)
+// ---------------------------------------------------------------------------
+
+/**
+ * Visual explosion radius (tiles) for each nuke type, used for shockwave and
+ * debris scatter sizing.
+ *
+ * Source: FxLayer.ts, inside the unit-death event handler:
+ *   case UnitType.AtomBomb:    this.onNukeEvent(unit, 70)
+ *   case UnitType.MIRVWarhead: this.onNukeEvent(unit, 70)
+ *   case UnitType.HydrogenBomb: this.onNukeEvent(unit, 160)
+ *
+ * Note: these are visual-only radii. The gameplay damage radii are separate
+ * and come from DefaultConfig.nukeMagnitudes() → { inner, outer }.
+ */
+export const NUKE_EXPLOSION_RADII: Readonly<Record<string, number>> = {
+  [UT_ATOM_BOMB]: 70,
+  [UT_HYDROGEN_BOMB]: 160,
+  [UT_MIRV_WARHEAD]: 70,
+};
+
+// ---------------------------------------------------------------------------
+// SAM range formula
+// ---------------------------------------------------------------------------
+
+/**
+ * SAM Launcher coverage radius in tiles at a given upgrade level.
+ * Source: DefaultConfig.samRange(level):
+ *   return this.maxSamRange() - 480 / (level + 5)
+ *   where maxSamRange() → return 150
+ */
+export function samRange(level: number): number {
+  return 150 - 480 / (level + 5);
+}
+
+// ---------------------------------------------------------------------------
+// Missile readiness formula
+// ---------------------------------------------------------------------------
+
+/**
+ * Fractional missile readiness [0, 1] for a Silo or SAM Launcher.
+ * Returns 1.0 when fully loaded, 0.0 when completely empty with no partial reload.
+ *
+ * Source: adapted from upstream readiness display logic (UILayer / FxLayer).
+ * Uses per-type cooldown: SAMCooldown() = 120, SiloCooldown() = 75.
+ */
+export function missileReadiness(
+  unitType: string,
+  level: number,
+  missileTimerQueue: number[],
+  gameTick: number,
+): number {
+  const cooldown =
+    unitType === UT_SAM_LAUNCHER ? SAM_COOLDOWN_TICKS : SILO_COOLDOWN_TICKS;
+  const maxMissiles = level;
+  const reloading = missileTimerQueue.length;
+  if (reloading === 0) return 1;
+
+  const ready = maxMissiles - reloading;
+  if (ready === 0 && maxMissiles > 1) return 0;
+
+  let readiness = ready / maxMissiles;
+  for (const timer of missileTimerQueue) {
+    const progress = gameTick - timer;
+    const ratio = progress / cooldown;
+    readiness += ratio / maxMissiles;
+  }
+  return Math.max(0, Math.min(1, readiness));
+}