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>

frontend/src/types/game.ts

@@ -1,9 +1,4 @@
-export type GameCategory =
-  | 'original'
-  | 'remake'
-  | 'enhanced'
-  | 'sequel'
-  | 'spinoff'
+export type GameCategory = 'original' | 'remake' | 'enhanced' | 'sequel' | 'spinoff'
 
 export interface Game {
   id: number
@@ -152,19 +147,19 @@ export interface UpdateRunInput {
 export interface CreateEncounterInput {
   routeId: number
   pokemonId: number
-  nickname?: string
+  nickname?: string | undefined
   status: EncounterStatus
-  catchLevel?: number
-  isShiny?: boolean
-  origin?: string
+  catchLevel?: number | undefined
+  isShiny?: boolean | undefined
+  origin?: string | undefined
 }
 
 export interface UpdateEncounterInput {
-  nickname?: string
-  status?: EncounterStatus
-  faintLevel?: number
-  deathCause?: string
-  currentPokemonId?: number
+  nickname?: string | undefined
+  status?: EncounterStatus | undefined
+  faintLevel?: number | undefined
+  deathCause?: string | undefined
+  currentPokemonId?: number | undefined
 }
 
 // Boss battles

frontend/src/types/rules.ts

@@ -60,8 +60,7 @@ export const RULE_DEFINITIONS: RuleDefinition[] = [
   {
     key: 'nicknameRequired',
     name: 'Nickname Required',
-    description:
-      'All caught Pokémon must be given a nickname to form a stronger bond.',
+    description: 'All caught Pokémon must be given a nickname to form a stronger bond.',
     category: 'core',
   },
   {
@@ -90,8 +89,7 @@ export const RULE_DEFINITIONS: RuleDefinition[] = [
   {
     key: 'hardcoreMode',
     name: 'Hardcore Mode',
-    description:
-      'No items may be used during battle. Held items are still allowed.',
+    description: 'No items may be used during battle. Held items are still allowed.',
     category: 'difficulty',
   },
   {