[serabi]

Change description

The goal of this PR is to add swarm conditions to the HeartGold and SoulSilver encounters at the S.S. Anne dock (location-area 349). The dock has the swarm slots, but nothing in the API currently marks them as swarm-only. Because of that, surfing adds up to 160%, and the extra Magikarp fishing slots mentioned in the issue show up all the time.

For each version, this adds swarm-yes to the swarm slot and swarm-no to the regular slot it replaces:

• Surfing slot 1: Wingull (swarm) and Tentacool
• Good Rod slots 3 and 4: Magikarp (swarm) and Chinchou or Shellder
• Super Rod slots 1-5: Magikarp (swarm) and the regular species

Old Rod slot 3 and Good Rod slot 1 are already Magikarp, so the swarm doesn't change them and they stay as they are.

The main Vermilion City area (282) already tags its Wingull surfing swarm the same way.

Closes #1110.

References

• HGSS's disassembled encounter data sets Vermilion's (T06) surfing swarm to Wingull and its fishing swarm to Magikarp:
  https://github.com/pret/pokeheartgold/blob/6bf138d6035aa6b43d6f8f4132a12df70f86dcec/files/fielddata/encountdata/gs_enc_data.json#L19305
  https://github.com/pret/pokeheartgold/blob/6bf138d6035aa6b43d6f8f4132a12df70f86dcec/files/fielddata/encountdata/gs_enc_data.json#L19493-L19495
• The surfing swarm replaces the first surfing slot, and the fishing swarm replaces Old Rod slot 3, Good Rod slots 1, 3 and 4, and every Super Rod slot:
  https://github.com/pret/pokeheartgold/blob/6bf138d6035aa6b43d6f8f4132a12df70f86dcec/src/field/encounter_check.c#L174-L212
  https://github.com/pret/pokeheartgold/blob/6bf138d6035aa6b43d6f8f4132a12df70f86dcec/src/field/encounter_check.c#L308
• The dock's HGSS encounters, including the untagged swarm rows:
  https://github.com/PokeAPI/pokeapi/blob/8a92bfa7dab2f12b84b5d151562f9857c133ff30/data/v2/csv/encounters.csv#L22881-L22936
• Vermilion City's existing Wingull swarm tags:
  https://github.com/PokeAPI/pokeapi/blob/8a92bfa7dab2f12b84b5d151562f9857c133ff30/data/v2/csv/encounter_condition_value_map.csv#L6495-L6496

Testing

Built the local database before and after the change and checked the S.S. Anne dock location-area endpoint.

Surfing and each rod now total 100% both with and without a swarm, in both versions.

All 69 tests passed, along with pre-commit, lint, formatting and type checks.

AI coding assistance disclosure

I used AI assistance from Claude Code (Claude Opus 5.5) to investigate the issue, compare PokeAPI's CSV records with HGSS's disassembled encounter data and code, and apply the fix. I then reviewed all of the code manually. All decisions made - and the PR text - are my own.

Contributor check list

• I have written a description of the contribution and explained its motivation.
• I have written tests for my code changes (if applicable).
• I have read and understood the AI Assisted Contribution guidelines.
• I will own this change in production, and I am prepared to fix any bugs caused by my code change.