chore: initial monorepo scaffold

Setup pnpm workspaces with apps/{web,api} placeholders and shared
packages: tsconfig, eslint-config, shared, ui, db. Includes Prettier,
ESLint, Husky pre-commit, lint-staged, EditorConfig, VSCode settings.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/tsconfig/base.json

@@ -0,0 +1,30 @@
+{
+  "$schema": "https://json.schemastore.org/tsconfig",
+  "display": "Base",
+  "compilerOptions": {
+    "target": "ES2022",
+    "lib": ["ES2022"],
+    "module": "ESNext",
+    "moduleResolution": "Bundler",
+    "esModuleInterop": true,
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "verbatimModuleSyntax": true,
+
+    "strict": true,
+    "noUncheckedIndexedAccess": true,
+    "exactOptionalPropertyTypes": true,
+    "noImplicitOverride": true,
+    "noFallthroughCasesInSwitch": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+
+    "declaration": true,
+    "declarationMap": true,
+    "sourceMap": true,
+    "incremental": true
+  }
+}