T-1: initialize monorepo structure with backend and frontend scaffolds

Backend: Spring Boot 3.5.11 on Java 25, Maven with wrapper, hexagonal
architecture package layout (domain/application/adapter/config), health
endpoint with integration test. Originally planned for Spring Boot 4.0
but pivoted due to massive package reorganization in 4.0 (see addenda
in research and plan docs).

Frontend: Vue 3 scaffolded via create-vue with TypeScript, Vue Router,
Vitest, ESLint, Prettier. Pivoted from Svelte due to ecosystem maturity
concerns (broken router ecosystem for Svelte 5).

Also: extended .gitignore for Java/Maven and Node/Vue artifacts, updated
CLAUDE.md with tech stack, build commands, agent documentation sections,
and document integrity rule.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/tsconfig.node.json

@@ -0,0 +1,28 @@
+// TSConfig for modules that run in Node.js environment via either transpilation or type-stripping.
+{
+  "extends": "@tsconfig/node24/tsconfig.json",
+  "include": [
+    "vite.config.*",
+    "vitest.config.*",
+    "cypress.config.*",
+    "nightwatch.conf.*",
+    "playwright.config.*",
+    "eslint.config.*"
+  ],
+  "compilerOptions": {
+    // Most tools use transpilation instead of Node.js's native type-stripping.
+    // Bundler mode provides a smoother developer experience.
+    "module": "preserve",
+    "moduleResolution": "bundler",
+
+    // Include Node.js types and avoid accidentally including other `@types/*` packages.
+    "types": ["node"],
+
+    // Disable emitting output during `vue-tsc --build`, which is used for type-checking only.
+    "noEmit": true,
+
+    // `vue-tsc --build` produces a .tsbuildinfo file for incremental type-checking.
+    // Specified here to keep it out of the root directory.
+    "tsBuildInfoFile": "./node_modules/.tmp/tsconfig.node.tsbuildinfo"
+  }
+}