Testing infrastructure, fix truncating of dataURLs (#26)

* feat: implement comprehensive testing infrastructure

- Fix image dataURL truncation bug in security.ts with configurable size limits
- Add backend integration tests (22 tests) with Vitest for API validation
- Add frontend unit tests (11 tests) for JSON serialization
- Implement browser-based E2E tests (8 tests) with Playwright
- Create Docker setup for repeatable E2E testing environment
- Add GitHub Actions CI workflow for automated testing
- Update .gitignore for test artifacts and temporary files

Testing Infrastructure:
- Backend: Vitest + Supertest for API integration tests
- Frontend: Vitest + Testing Library for component tests
- E2E: Playwright with Chromium for full browser automation
- CI/CD: GitHub Actions with parallel test execution

Security Improvements:
- Make dataURL size limit configurable (default: 10MB)
- Enhanced validation for image dataURLs
- Block malicious content (javascript:, script tags)

All tests pass: 41 total (22 backend + 11 frontend + 8 E2E)

* feat(tests): add comprehensive E2E tests for dashboard workflows and image persistence
chore(env): update environment variables for consistent API URL usage
fix(api): centralize API request helpers for drawing and collection management
style(DrawingCard): enhance accessibility with ARIA attributes and data-testid for testing

* cleanup/revise documentation

* cleanup/revise documentation

* Add end-to-end tests for drawing CRUD, export/import, search/sort, and theme toggle functionalities

- Implemented E2E tests for drawing creation, editing, and deletion in `drawing-crud.spec.ts`.
- Added tests for export and import features, including JSON and SQLite formats in `export-import.spec.ts`.
- Created tests for searching and sorting drawings by name and date in `search-and-sort.spec.ts`.
- Developed tests for theme toggle functionality to ensure persistence across sessions in `theme-toggle.spec.ts`.

* fix: exclude test files from production build to fix Docker build

* feat: implement comprehensive testing infrastructure (#19)

* bump version 0.1.7

* feat: implement comprehensive testing infrastructure

- Fix image dataURL truncation bug in security.ts with configurable size limits
- Add backend integration tests (22 tests) with Vitest for API validation
- Add frontend unit tests (11 tests) for JSON serialization
- Implement browser-based E2E tests (8 tests) with Playwright
- Create Docker setup for repeatable E2E testing environment
- Add GitHub Actions CI workflow for automated testing
- Update .gitignore for test artifacts and temporary files

Testing Infrastructure:
- Backend: Vitest + Supertest for API integration tests
- Frontend: Vitest + Testing Library for component tests
- E2E: Playwright with Chromium for full browser automation
- CI/CD: GitHub Actions with parallel test execution

Security Improvements:
- Make dataURL size limit configurable (default: 10MB)
- Enhanced validation for image dataURLs
- Block malicious content (javascript:, script tags)

All tests pass: 41 total (22 backend + 11 frontend + 8 E2E)

* feat(tests): add comprehensive E2E tests for dashboard workflows and image persistence
chore(env): update environment variables for consistent API URL usage
fix(api): centralize API request helpers for drawing and collection management
style(DrawingCard): enhance accessibility with ARIA attributes and data-testid for testing

* Add end-to-end tests for drawing CRUD, export/import, search/sort, and theme toggle functionalities

- Implemented E2E tests for drawing creation, editing, and deletion in `drawing-crud.spec.ts`.
- Added tests for export and import features, including JSON and SQLite formats in `export-import.spec.ts`.
- Created tests for searching and sorting drawings by name and date in `search-and-sort.spec.ts`.
- Developed tests for theme toggle functionality to ensure persistence across sessions in `theme-toggle.spec.ts`.

* Update backend/src/__tests__/testUtils.ts

---------

Co-authored-by: Zimeng Xiong <zxzimeng@gmail.com>
* version bump 0.1.8

* fix(ci): consolidate E2E server startup to prevent shell isolation issues

Background processes started with & in separate GitHub Actions run steps
can terminate when those steps complete because each step creates a new
shell. This caused the backend and frontend servers to die before the
E2E tests could run.

Fixed by consolidating server startup and test execution into a single
shell step with:
- Proper PID tracking for cleanup
- Health check loops instead of fixed sleep times
- All processes run in the same shell session

* fix(ci): use absolute database path for E2E tests

* fix(backend): use resolved DATABASE_URL path for export/import endpoints

---------

Co-authored-by: Adrian Acala <adrianacala017@gmail.com>

e2e/fixtures/small-image.excalidraw

@@ -0,0 +1,51 @@
+{
+  "type": "excalidraw",
+  "version": 2,
+  "source": "https://excalidash.test",
+  "elements": [
+    {
+      "id": "test-image-element",
+      "type": "image",
+      "x": 100,
+      "y": 100,
+      "width": 200,
+      "height": 150,
+      "angle": 0,
+      "strokeColor": "transparent",
+      "backgroundColor": "transparent",
+      "fillStyle": "solid",
+      "strokeWidth": 2,
+      "strokeStyle": "solid",
+      "roughness": 1,
+      "opacity": 100,
+      "groupIds": [],
+      "frameId": null,
+      "index": "a0",
+      "roundness": null,
+      "seed": 1234567890,
+      "version": 1,
+      "versionNonce": 987654321,
+      "isDeleted": false,
+      "boundElements": null,
+      "updated": 1700000000000,
+      "link": null,
+      "locked": false,
+      "fileId": "embedded-test-image",
+      "scale": [1, 1]
+    }
+  ],
+  "appState": {
+    "gridSize": 20,
+    "gridStep": 5,
+    "gridModeEnabled": false,
+    "viewBackgroundColor": "#ffffff"
+  },
+  "files": {
+    "embedded-test-image": {
+      "id": "embedded-test-image",
+      "mimeType": "image/png",
+      "dataURL": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg==",
+      "created": 1700000000000
+    }
+  }
+}