Add test and security baseline

- make quick/check/mutation from cj/security-baseline (Makefile unchanged,
  settings in baseline.mk), pre-commit, gitleaks, Semgrep rules, ESLint
  security rules, Forgejo workflow
- tests/security: generic baseline tests plus app config and role tests
  against createApp() with an in-memory database
- extract createApp() from src/server/index.ts; LB_DATABASE_PATH for tests
- fix gaps found by the tests: reject unknown fields on project create,
  answer malformed JSON with 400 instead of 500, set nosniff on the API
- npm audit fix (next 16.4.1 and others, no high/critical left)
- clear ESLint errors, safeFileName without control-character regex
- per-project ownership stays an open, documented gap (idorGap -> TODO)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/db/repositories/external-object-new-circuit-project-command.repository.ts

@@ -7,7 +7,6 @@ import {
   invertExternalObjectNewCircuitProjectCommand,
   type ExternalObjectNewCircuitProjectCommand,
 } from "../../domain/models/external-object-new-circuit-project-command.model.js";
-import type { CircuitDeviceRowSnapshot } from "../../domain/models/circuit-device-row-structure-project-command.model.js";
 import type { CircuitSnapshot } from "../../domain/models/circuit-structure-project-command.model.js";
 import type { ExternalObjectNewCircuitProjectCommandStore } from "../../domain/ports/external-object-new-circuit-project-command.store.js";
 import { parseGroupedEquipmentIdentifier } from "../../domain/services/circuit-group-numbering.js";