feat: NTE gear optimizer web app

Client-side optimizer for Neverness to Everness console builds. Imports a
gear export from nte-history-exporter, keeps it in IndexedDB, and solves for
the best module placement per character or across a team.

- domain/: pure ports of the Python research scripts (shapes, cartridges,
  board tiling, stats, scoring, set bonuses, Arc effects, sheet prediction).
  No DOM, no storage imports, so they stay worker-safe and Node-testable.
- solver/: single-character solve with branch and bound, plus a three-phase
  team solve (portfolio, leximin, column generation) over disjoint item sets.
  Runs in a Worker when one can be constructed, inline otherwise.
- db/: three storage tiers selected by use rather than feature detection,
  fail-closed import validation, and undo that restores both sides of a steal.
- ui/: React 19 views for items, characters and teams; the board is drawn as
  the deliverable rather than a score.
- Two build targets: a hosted bundle and a single self-contained nte.html
  with no external requests.

Values the model cannot measure are reported as unavailable rather than
guessed: cartridge set bonuses, the level 80 base-stat multiplier, and the
distinction between "optimal for this packing" and globally optimal.

145 tests, tsc clean, both build targets clean.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

vite.config.ts

@@ -0,0 +1,16 @@
+import { defineConfig } from "vite";
+import react from "@vitejs/plugin-react";
+
+// `base: './'` keeps the build working unchanged at nte.goober.moe, under a
+// plain `python3 -m http.server -d dist`, and inside the single-file build.
+export default defineConfig({
+  base: "./",
+  plugins: [react()],
+  build: {
+    target: "es2022",
+    outDir: "dist",
+    assetsInlineLimit: 4096,
+    sourcemap: false,
+  },
+  worker: { format: "es" },
+});