Align repo config with global development standards

- Add missing tsconfig strictness flags (noUncheckedIndexedAccess,
  exactOptionalPropertyTypes, noImplicitOverride,
  noPropertyAccessFromIndexSignature) and fix all resulting type errors
- Replace ESLint/Prettier with oxlint 1.48.0 and oxfmt 0.33.0
- Pin all frontend and backend dependencies to exact versions
- Pin GitHub Actions to SHA hashes with persist-credentials: false
- Fix CI Python version mismatch (3.12 -> 3.14) and ruff target-version
- Add vitest 4.0.18 with jsdom environment for frontend testing
- Add ty 0.0.17 for Python type checking (non-blocking in CI)
- Add actionlint and zizmor CI job for workflow linting and security audit
- Add Dependabot config for npm, pip, and github-actions
- Update CLAUDE.md and pre-commit hooks to reflect new tooling
- Ignore Claude Code sandbox artifacts in gitignore

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.beans/nuzlocke-tracker-zom1--add-missing-tsconfig-strictness-flags.md

@@ -0,0 +1,19 @@
+---
+# nuzlocke-tracker-zom1
+title: Add missing tsconfig strictness flags
+status: completed
+type: task
+priority: normal
+created_at: 2026-02-16T19:13:49Z
+updated_at: 2026-02-16T19:24:15Z
+parent: nuzlocke-tracker-a5es
+---
+
+tsconfig.app.json is missing 4 required strict flags from the global standards:
+
+- noUncheckedIndexedAccess: true
+- exactOptionalPropertyTypes: true
+- noImplicitOverride: true
+- noPropertyAccessFromIndexSignature: true
+
+These need to be added and any resulting type errors fixed.