Restructure into pnpm monorepo with game shell, docs, and SpacetimeDB backend

- Restructure flat static prototype into pnpm workspace monorepo
- apps/game: playable shell with R3F 3D scene, HUD, SpacetimeDB connection
- apps/docs: design docs and prototypes
- apps/site: landing page
- packages/ui: shared Button and Panel primitives
- services/spacetimedb: backend module (9 tables, 11 reducers)
- Archive legacy static files to archive/legacy-static/
- Game loop: connect, undock, target, approach, dock, mine, sell
- Add pnpm-workspace.yaml, tsconfig.base.json, spacetime.json

archive/legacy-static/css/base.css

@@ -0,0 +1,71 @@
+/* ============================================================
+   Base — Reset + Typography
+   ============================================================ */
+*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
+
+html {
+  font-size: 14px;
+  -webkit-font-smoothing: antialiased;
+  -moz-osx-font-smoothing: grayscale;
+  text-rendering: optimizeLegibility;
+}
+
+body {
+  font-family: var(--font-body);
+  color: var(--fg);
+  background: var(--bg);
+  line-height: 1.6;
+  overflow: hidden;
+  height: 100vh;
+}
+
+#root { height: 100vh; display: flex; }
+
+a { color: var(--cyan); text-decoration: none; transition: color var(--transition-fast); }
+a:hover { color: var(--accent); }
+
+h1, h2, h3, h4, h5, h6 {
+  font-family: var(--font-display);
+  color: var(--fg-bright);
+  line-height: 1.25;
+  letter-spacing: -0.01em;
+}
+h1 { font-size: 2rem; font-weight: 700; }
+h2 { font-size: 1.5rem; font-weight: 600; margin-bottom: var(--sp-4); }
+h3 { font-size: 1.2rem; font-weight: 600; margin-bottom: var(--sp-3); }
+h4 { font-size: 1.05rem; font-weight: 600; margin-bottom: var(--sp-2); }
+
+p { margin-bottom: var(--sp-4); }
+
+code {
+  font-family: var(--font-mono);
+  font-size: 0.9em;
+  background: var(--surface-raised);
+  padding: 2px 6px;
+  border-radius: var(--radius-sm);
+  color: var(--accent);
+}
+
+pre {
+  font-family: var(--font-mono);
+  font-size: 0.85rem;
+  background: var(--surface);
+  border: 1px solid var(--border);
+  border-radius: var(--radius-md);
+  padding: var(--sp-4);
+  overflow-x: auto;
+  line-height: 1.5;
+  margin-bottom: var(--sp-4);
+}
+
+ul, ol { padding-left: var(--sp-6); margin-bottom: var(--sp-4); }
+li { margin-bottom: var(--sp-1); }
+
+::selection { background: var(--accent); color: var(--bg); }
+
+* { scrollbar-width: thin; scrollbar-color: var(--border-light) transparent; }
+
+::-webkit-scrollbar { width: 6px; height: 6px; }
+::-webkit-scrollbar-track { background: transparent; }
+::-webkit-scrollbar-thumb { background: var(--border-light); border-radius: var(--radius-pill); }
+::-webkit-scrollbar-thumb:hover { background: var(--muted); }