Phase 0 scaffold: SvelteKit 5 + Drizzle + auth + storage interface

Stack matches sibling buildfor_life_* apps: SvelteKit 5 with adapter-node,
Svelte 5 runes, TypeScript, Tailwind v4 with @theme inline tokens,
PostgreSQL via Drizzle ORM, Argon2id sessions via @node-rs/argon2 and
@oslojs/crypto, EasyMDE ready for wiki/decision markdown, Sharp for
thumbnails.

Included in this commit:
- Config: package.json, svelte.config.js, vite.config.ts, tsconfig.json,
  drizzle.config.ts, .gitignore, .env.example, .gitattributes, .npmrc
- Tenancy schema: companies, users, company_users, sessions
  (10 enums pre-declared for the full domain so downstream migrations
   don't re-diff them; decision_scope widened to include asset +
   work_package per product decision)
- Auth: password hashing + SHA-256-hashed session cookies,
  session lifetime 30d with sliding renewal at T-15d,
  login + logout + session refresh in hooks
- Storage: StorageAdapter interface + LocalDiskStorage with HMAC-signed
  URLs served by /api/files, S3 drop-in with zero schema change
- UI shell: dark-mode bootstrap in app.html identical to siblings,
  sidebar (w-64, h-14 header, amber attention band pattern from repair),
  topbar with breadcrumbs, theme toggle with cross-tab sync via
  storage event, blue-600 primary, responsive drawer
- Routes: (app) authed group with auto-redirect to /login,
  (auth) login group, dashboard placeholder, error page, signed-file API
- Scripts: create-user script for bootstrapping first admin user
- Drizzle: initial migration generated (0000_init.sql)
- Shared agents and skills committed under .claude/; per-user
  permissions gitignored

Typecheck: 0 errors / 0 warnings across 555 files.

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

drizzle/README.md

@@ -0,0 +1,18 @@
+# drizzle migrations
+
+This directory holds SQL migrations generated by `drizzle-kit generate` from the
+TypeScript schema in `src/lib/server/db/schema/`.
+
+Commands:
+
+- `npm run db:generate` — diff the schema vs. the latest snapshot and emit a new `.sql` file
+- `npm run db:migrate` — apply pending migrations to `DATABASE_URL`
+- `npm run db:push` — skip migrations and sync the schema directly (**dev only**)
+- `npm run db:studio` — open the Drizzle Studio UI
+
+After every generate, review the SQL for surprises — especially around:
+
+- enum additions (non-blocking) vs. removals (require a separate data migration)
+- index changes on large tables (use `CONCURRENTLY` in production rollouts)
+- anything touching `assets.custom_fields` — see `project_buildfor_life_ops.md`
+  memory for the immutable-key policy.