Initial scaffold: tooling, plan, task briefs

- pnpm 10 workspace + TypeScript strict + ESLint flat + Prettier
- CLAUDE.md as canonical brief
- docs/tasks/ — 22 task briefs broken out by phase for sub-sessions
- docs/decisions/ — ADR scaffold

Implements task 01 (repo-init).

.gitignore

@@ -0,0 +1,43 @@
+# Dependencies
+node_modules/
+.pnpm-store/
+
+# Build output
+.next/
+out/
+dist/
+build/
+*.tsbuildinfo
+
+# Env
+.env
+.env.local
+.env.*.local
+.env.production
+
+# Logs
+*.log
+npm-debug.log*
+pnpm-debug.log*
+
+# OS
+.DS_Store
+Thumbs.db
+desktop.ini
+
+# Editors
+.vscode/*
+!.vscode/extensions.json
+!.vscode/settings.json.example
+.idea/
+
+# Coverage / test artifacts
+coverage/
+playwright-report/
+test-results/
+
+# Drizzle generated artifacts (migrations themselves are committed)
+drizzle/meta/
+
+# Backups
+deploy/backups/data/