Major refactor: auth, bug fixes, security hardening, modular routes

Bug fixes
- Sync database.js schema with actual production DB (tarifoptionen
  shape was wrong; new installs would have broken).
- Fix SQL syntax error `SELECT to.*` (reserved keyword) in single-
  schaltung provision endpoint, plus the dead fallback hierarchy
  that selected columns that were never in the query.
- Fix PUT /api/tarifoptionen/:id writing to non-existent column
  provision_betrag (should be provision_euro).
- Fix race condition in PUT /api/schaltungen/:id where forEach with
  async db.run inside a transaction could send duplicate responses.
- Delete dokumente rows explicitly before deleting schaltung
  (existing DBs lack ON DELETE CASCADE on dokumente FK).
- Replace hardcoded basisBetrag=100 for percent rules; basis is now
  configurable per rule via the new basis_euro column.

Security
- Multi-user authentication: users table, bcryptjs, express-session
  with SQLite store, login/logout/me/setup/change-password endpoints.
- Auth gate on all /api/* except /api/auth/*.
- CLI to create users: npm run create-user -- <user> <pass> [--admin].
- helmet for security headers.
- CORS restricted to ALLOWED_ORIGINS env (default same-origin).
- Rate limits: 300/min global, 20/15min on login.
- Path-traversal validation on document download/delete.
- XSS hardening in frontend: escapeHtml helper applied to all
  DB-derived innerHTML interpolations; inline onclick handlers that
  embedded user-controlled strings replaced with data-* attrs +
  addEventListener.

Architecture
- Provision calculation centralised in provisionService.js as the
  single source of truth (was duplicated and inconsistent).
- server.js cut from 2138 to ~140 lines; routes split into per-
  resource modules under routes/.
- Promise wrapper db.js for sqlite3 callbacks; async/await in routes.
- middleware/ for auth and async error handling.

Tests
- 14 unit tests for provisionService covering fallback hierarchy,
  percent calculation, tarifoptionen, hardware logic, employee
  commission. All green.

Config
- dotenv loads .env.local at startup (gitignored).
- .gitignore extended for sessions.db and .env*.

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

package-lock.json

@@ -8,8 +8,14 @@
       "name": "provision-tracker",
       "version": "1.0.0",
       "dependencies": {
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+        "connect-sqlite3": "^0.9.13",
         "cors": "^2.8.5",
+        "dotenv": "^17.4.2",
         "express": "^4.18.2",
+        "express-rate-limit": "^7.4.0",
+        "express-session": "^1.18.0",
+        "helmet": "^7.1.0",
         "multer": "^1.4.5-lts.1",
         "sqlite3": "^5.1.6"
       },
@@ -237,6 +243,11 @@
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       ]
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+    "node_modules/bcryptjs": {
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+      "resolved": "https://registry.npmjs.org/bcryptjs/-/bcryptjs-2.4.3.tgz",
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@@ -510,6 +521,17 @@
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+      "resolved": "https://registry.npmjs.org/connect-sqlite3/-/connect-sqlite3-0.9.16.tgz",
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@@ -626,6 +648,17 @@
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+      "resolved": "https://registry.npmjs.org/dotenv/-/dotenv-17.4.2.tgz",
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+      "engines": {
+        "node": ">=12"
+      },
+      "funding": {
+        "url": "https://dotenvx.com"
+      }
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     "node_modules/dunder-proto": {
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       "resolved": "https://registry.npmjs.org/dunder-proto/-/dunder-proto-1.0.1.tgz",
@@ -795,6 +828,55 @@
         "url": "https://opencollective.com/express"
       }
     },
+    "node_modules/express-rate-limit": {
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+      "resolved": "https://registry.npmjs.org/express-rate-limit/-/express-rate-limit-7.5.1.tgz",
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+      "engines": {
+        "node": ">= 16"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/express-rate-limit"
+      },
+      "peerDependencies": {
+        "express": ">= 4.11"
+      }
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+    "node_modules/express-session": {
+      "version": "1.19.0",
+      "resolved": "https://registry.npmjs.org/express-session/-/express-session-1.19.0.tgz",
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+        "cookie-signature": "~1.0.7",
+        "debug": "~2.6.9",
+        "depd": "~2.0.0",
+        "on-headers": "~1.1.0",
+        "parseurl": "~1.3.3",
+        "safe-buffer": "~5.2.1",
+        "uid-safe": "~2.1.5"
+      },
+      "engines": {
+        "node": ">= 0.8.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/express"
+      }
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+    "node_modules/express-session/node_modules/cookie": {
+      "version": "0.7.2",
+      "resolved": "https://registry.npmjs.org/cookie/-/cookie-0.7.2.tgz",
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+      "engines": {
+        "node": ">= 0.6"
+      }
+    },
+    "node_modules/express-session/node_modules/cookie-signature": {
+      "version": "1.0.7",
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+      "integrity": "sha512-NXdYc3dLr47pBkpUCHtKSwIOQXLVn8dZEuywboCOJY/osA0wFSLlSawr3KN8qXJEyX66FcONTH8EIlVuK0yyFA=="
+    },
     "node_modules/file-uri-to-path": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/file-uri-to-path/-/file-uri-to-path-1.0.0.tgz",
@@ -1036,6 +1118,14 @@
         "node": ">= 0.4"
       }
     },
+    "node_modules/helmet": {
+      "version": "7.2.0",
+      "resolved": "https://registry.npmjs.org/helmet/-/helmet-7.2.0.tgz",
+      "integrity": "sha512-ZRiwvN089JfMXokizgqEPXsl2Guk094yExfoDXR0cBYWxtBbaSww/w+vT4WEJsBW2iTUi1GgZ6swmoug3Oy4Xw==",
+      "engines": {
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+      }
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     "node_modules/http-cache-semantics": {
       "version": "4.2.0",
       "resolved": "https://registry.npmjs.org/http-cache-semantics/-/http-cache-semantics-4.2.0.tgz",
@@ -1738,6 +1828,14 @@
         "node": ">= 0.8"
       }
     },
+    "node_modules/on-headers": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/on-headers/-/on-headers-1.1.0.tgz",
+      "integrity": "sha512-737ZY3yNnXy37FHkQxPzt4UZ2UWPWiCZWLvFZ4fu5cueciegX0zGPnrlY6bwRg4FdQOe9YU8MkmJwGhoMybl8A==",
+      "engines": {
+        "node": ">= 0.8"
+      }
+    },
     "node_modules/once": {
       "version": "1.4.0",
       "resolved": "https://registry.npmjs.org/once/-/once-1.4.0.tgz",
@@ -1885,6 +1983,14 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/random-bytes": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/random-bytes/-/random-bytes-1.0.0.tgz",
+      "integrity": "sha512-iv7LhNVO047HzYR3InF6pUcUsPQiHTM1Qal51DcGSuZFBil1aBBWG5eHPNek7bvILMaYJ/8RU1e8w1AMdHmLQQ==",
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+      }
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       "resolved": "https://registry.npmjs.org/range-parser/-/range-parser-1.2.1.tgz",
@@ -2509,6 +2615,17 @@
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     },
+    "node_modules/uid-safe": {
+      "version": "2.1.5",
+      "resolved": "https://registry.npmjs.org/uid-safe/-/uid-safe-2.1.5.tgz",
+      "integrity": "sha512-KPHm4VL5dDXKz01UuEd88Df+KzynaohSL9fBh096KWAxSKZQDI2uBrVqtvRM4rwrIrRRKsdLNML/lnaaVSRioA==",
+      "dependencies": {
+        "random-bytes": "~1.0.0"
+      },
+      "engines": {
+        "node": ">= 0.8"
+      }
+    },
     "node_modules/undefsafe": {
       "version": "2.0.5",
       "resolved": "https://registry.npmjs.org/undefsafe/-/undefsafe-2.0.5.tgz",