Add pre-commit hooks for linting and formatting

Set up pre-commit framework with ruff (backend) and ESLint/Prettier/tsc
(frontend) hooks to catch issues locally before CI. Auto-format all
frontend files with Prettier to comply with the new check.

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

frontend/src/api/encounters.ts

@@ -9,14 +9,14 @@ import type {
 
 export function createEncounter(
   runId: number,
-  data: CreateEncounterInput,
+  data: CreateEncounterInput
 ): Promise<EncounterDetail> {
   return api.post(`/runs/${runId}/encounters`, data)
 }
 
 export function updateEncounter(
   id: number,
-  data: UpdateEncounterInput,
+  data: UpdateEncounterInput
 ): Promise<EncounterDetail> {
   return api.patch(`/encounters/${id}`, data)
 }
@@ -25,7 +25,10 @@ export function deleteEncounter(id: number): Promise<void> {
   return api.del(`/encounters/${id}`)
 }
 
-export function fetchEvolutions(pokemonId: number, region?: string): Promise<Evolution[]> {
+export function fetchEvolutions(
+  pokemonId: number,
+  region?: string
+): Promise<Evolution[]> {
   const params = region ? `?region=${encodeURIComponent(region)}` : ''
   return api.get(`/pokemon/${pokemonId}/evolutions${params}`)
 }
@@ -34,6 +37,8 @@ export function fetchForms(pokemonId: number): Promise<Pokemon[]> {
   return api.get(`/pokemon/${pokemonId}/forms`)
 }
 
-export function bulkRandomizeEncounters(runId: number): Promise<{ created: unknown[]; skippedRoutes: number }> {
+export function bulkRandomizeEncounters(
+  runId: number
+): Promise<{ created: unknown[]; skippedRoutes: number }> {
   return api.post(`/runs/${runId}/encounters/bulk-randomize`, {})
 }