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>

README.md

@@ -0,0 +1,63 @@
+# nte-optimizer
+
+> [!CAUTION]
+> **This repository is vibecoded.** Its implementation was written with substantial AI assistance and may contain plausible-looking mistakes, unsafe assumptions, or unreviewed edge cases. Treat it with care: inspect the code, verify outputs, and run the tests before relying on it.
+
+Gear optimizer for *Neverness to Everness*. Static site, no server, no account, and no runtime connection to the game.
+
+It imports a gear snapshot produced by `nte-exporter`, scores the available cartridges and modules, and draws recommended builds directly onto each character's console grid.
+
+## Features
+
+- Single-character optimization with Prydwen targets or custom targets and weights.
+- Cartridge set and 2-piece/4-piece bonus selection.
+- Arc stats, refinements, conditional-effect controls, and explicit notices for effects the model cannot score.
+- Team optimization against one shared item pool without assigning an item twice.
+- Console-grid layouts with module placement and enough item detail to find each piece in game.
+- Local equipment tracking, Equip/Undo, and import refreshes from game truth.
+- Predicted-versus-measured character sheet comparison.
+- Hosted build plus a single-file offline build.
+
+All account data stays in the browser. Nothing is uploaded by the app.
+
+## Running locally
+
+```sh
+npm ci
+npm run dev
+```
+
+Useful checks and builds:
+
+```sh
+npm test
+npm run check:guides
+npm run build          # hosted build in dist/
+npm run build:single   # standalone dist/nte.html
+```
+
+The standalone build works over `file://`. Browser restrictions disable workers, IndexedDB, and bundled artwork there; the app falls back to inline solving and localStorage or memory.
+
+## Model boundaries
+
+This is a stat-target optimizer, not a damage simulator. It has no rotation or ability-multiplier model.
+
+- Targets are floors. Published substat rankings determine their relative weights.
+- Timed bonuses are reported but not scored without defensible uptime data.
+- Shield strength, enemy resistance, ally-only buffs, and other unsupported quantities are marked unmodellable instead of mapped onto a different stat.
+- Level-80 base-stat scaling remains unmeasured, so dependent sheet values are shown as unavailable.
+- “Proven” means optimal for one packing and cartridge, not globally optimal across every internal beam-search choice.
+
+## Project layout
+
+| Path | Contents |
+|---|---|
+| `data-src/` | Source classifications, cartridge bonuses, and guide data. |
+| `tools/` | Data validation, generation, benchmarking, and build scripts. |
+| `src/domain/` | Pure stat, board, cartridge, Arc, and scoring logic. |
+| `src/solver/` | Worker-safe single-character and team solvers. |
+| `src/db/` | Import validation and local persistence. |
+| `src/ui/` | React interface. |
+| `tests/` | Domain, solver, persistence, and integration checks. |
+
+`src/domain/` and `src/solver/` stay free of DOM, storage, and UI imports so the same logic runs in tests, inline, or in a Web Worker.