Update project config for Go tool and port change

Add Go to .tool-versions, update .gitignore for Go build output and
cache, document seed data regeneration in README, and change API port
from 8000 to 8080 in docker-compose.

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

.beans/nuzlocke-tracker-338l--verify-fetch-pokeapipy-rewrite.md

@@ -0,0 +1,22 @@
+---
+# nuzlocke-tracker-338l
+title: Verify fetch_pokeapi.py rewrite
+status: in-progress
+type: task
+created_at: 2026-02-07T15:08:10Z
+updated_at: 2026-02-07T15:08:10Z
+---
+
+All code changes are complete. Run verification:
+1. Run the script to completion
+2. Verify output (pokemon.json has forms, correct IDs, etc.)
+3. Verify cache speedup on second run
+4. Frontend build check
+
+## Checklist
+- [ ] Run fetch_pokeapi.py to completion
+- [ ] Verify pokemon.json has more entries with forms (megas, gmax, regionals)
+- [ ] Verify pokeapi_id/national_dex split is correct
+- [ ] Verify route/encounter JSON files
+- [ ] Verify cache speedup on second run
+- [ ] Frontend build passes