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 +1,58 @@
+# nte-optimizer
+
+Gear optimizer for *Neverness to Everness*. Static site, no server, no account.
+
+It imports the JSON that [`nte-exporter`](../nte-exporter) writes during a normal
+capture run, and recommends what to equip on whom — drawn onto each character's
+console grid.
+
+## Running it
+
+```sh
+npm ci
+npm run dev            # development
+npm run build          # dist/index.html  — the normal build
+npm run build:single   # dist/nte.html    — one file, works over file://
+npm test
+```
+
+`dist/` is **committed on purpose**. In three years, when `npm ci` fails on some
+transitive native module, `python3 -m http.server -d dist` will still work. The
+source build is the convenience; the committed output is the artifact.
+
+## Layout
+
+| path | what lives there |
+|---|---|
+| `data-src/` | raw everness mirrors, Arc classifications, guide data. Committed, not shipped. |
+| `tools/` | build-time scripts. Output goes to `src/generated/`, also committed. |
+| `src/domain/` | **pure.** No DOM, no IndexedDB, no imports from `ui/`, `db/` or `state/`. |
+| `src/solver/` | same rule. Chunked generators, so they run in a worker or inline unchanged. |
+| `src/db/` | schema, migrations, import, persistence adapters. |
+| `src/ui/` | React. Four tabs and a hash router. |
+
+The `domain/` and `solver/` rule is what makes them worker-safe, Node-testable
+and diffable against the Python they were ported from. Keep it.
+
+## Two things that are easy to get wrong
+
+**Ported rules were expensive to derive and break in ways that still look
+plausible.** Before touching anything in `domain/`, read
+`~/Apps/nte-research/WIREFORMAT.md` and the "facts worth not re-deriving"
+section of `RESUME.md`. Builds are 6, 7 or 8 modules and never always 7; the
+console trait is not always CRIT DMG or Type III; a transposed board renders
+correctly on a symmetric grid.
+
+**The model has measured gaps, and the app is built to show them rather than
+hide them.** Set bonus values are unknown and contribute nothing. The base-stat
+multiplier has never been read at level 80. A `proven` build is optimal for its
+packing and cartridge, not globally. Every one of those is surfaced in the UI on
+purpose — if you find yourself replacing one with a plausible number, don't.
+
+## Degraded modes
+
+Opening `dist/nte.html` from the filesystem gives the page an opaque origin, so
+IndexedDB, workers, `fetch` and module scripts are all unavailable. The app
+handles this behind two interfaces it never sees through — `PersistenceAdapter`
+(IndexedDB → localStorage → memory) and `SolverHost` (worker → inline) — and
+shows a banner when storage is not durable. Artwork is not carried in that build.