feat(perf): swap React for @tanstack/dom-vite shim

Drop-in React-compatible shim (~9-10KB gzipped) replacing react / react-dom /
react-dom/server via the @tanstack/dom-vite Vite plugin. Installing just
@tanstack/dom-vite pulls the full set (dom-core, scheduler, react, react-dom,
react-dom-server) transitively.

Build-size win: app-shell + react gzip 160KB → 116KB (-44KB).
Mobile Lighthouse: slight improvement (-128ms FCP, -27ms TBT).
Desktop Lighthouse: parity with baseline.

Also:
- oxlint: ignore .claude/, disable nested config discovery so stale agent
  worktrees with their own oxlintrc copies don't break lint.

Author: tannerlinsley

.oxlintrc.json

@@ -19,7 +19,8 @@
     ".tanstack-start",
     ".netlify",
     "public",
-    "convex/.temp"
+    "convex/.temp",
+    ".claude"
   ],
   "rules": {
     "no-array-constructor": "error",

package.json

@@ -12,7 +12,7 @@
     "build": "vite build",
     "start": "vite start",
     "start:prod": "pnpm run with-env node scripts/run-built-server.mjs",
-    "lint": "oxlint --type-aware",
+    "lint": "oxlint --type-aware --disable-nested-config",
     "format": "oxfmt --write",
     "db:generate": "drizzle-kit generate",
     "db:migrate": "drizzle-kit migrate",
@@ -122,6 +122,7 @@
     "@playwright/test": "^1.59.0",
     "@shikijs/transformers": "^4.0.2",
     "@tanstack/devtools-vite": "^0.6.0",
+    "@tanstack/dom-vite": "0.1.0-alpha.2",
     "@tanstack/react-devtools": "^0.10.2",
     "@tanstack/react-query-devtools": "^5.99.0",
     "@types/hast": "^3.0.4",

pnpm-lock.yaml

@@ -1,5 +1,6 @@
 import { sentryTanstackStart } from '@sentry/tanstackstart-react/vite'
 import { defineConfig } from 'vite'
+import { tanstackDom } from '@tanstack/dom-vite'
 import contentCollections from '@content-collections/vite'
 import { devtools as tanstackDevtools } from '@tanstack/devtools-vite'
 import { tanstackStart } from '@tanstack/react-start/plugin/vite'
@@ -102,6 +103,12 @@ export default defineConfig({
       'discord-interactions',
       // Don't pre-bundle CLI so we always get fresh changes during dev
       ...(isDev ? ['@tanstack/cli'] : []),
+      // `use client` libraries that plugin-rsc pre-bundles inconsistently
+      // across client/ssr/rsc envs when combined with our React shim — each
+      // env resolves `react` to a different target, so the optimizer's hash
+      // diverges. Excluding from optimize keeps resolution deterministic per
+      // env and silences the 50k+ "inconsistently optimized" warning flood.
+      'lucide-react',
     ],
   },
   build: {
@@ -168,6 +175,7 @@ export default defineConfig({
     },
   },
   plugins: [
+    tanstackDom(),
     ...(isDev ? [tanstackDevtools()] : []),
     tanstackStart({
       rsc: {