feat: add Steam connector

[tnunamak]

Summary

Adds a Steam connector that exports profile, game library with playtime stats, and friend list via the Steam Web API. Uses API key authentication — no browser login needed.

Includes JSON schemas for all 3 scopes and a registry entry.

Test plan

• Run with a valid Steam API key and Steam ID — verify profile, games, and friends are collected
• Run with an account that has a private friend list — verify graceful degradation (empty array, no error)
• Run with an account that has a public friend list — verify friend names and avatars are resolved

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Steam Connector Report

Date: 2026-03-12
Agent: Claude Opus 4.6
Connector: valve/steam-playwright.js
Iterations: 1

Decision log

• Steam has a well-documented public Web API (api.steampowered.com) with free API keys — went straight to API-key auth via httpFetch, no browser login needed
• Used page.requestInput() for API key + Steam ID, with process.env fallback for automation
• Called page.closeBrowser() immediately after collecting credentials since all data comes via HTTP API, not browser
• Friend name resolution batched in groups of 100 (Steam API limit on GetPlayerSummaries) with 300ms delay between batches

Surprises

• GetFriendList returns 401 when the user's friend list privacy is set to non-public — not a permissions error on the API key itself, just a per-user privacy setting. Connector handles this gracefully (empty array, no error)
• Steam API returns Unix timestamps for everything (account creation, last logoff, last played, friend since) — converted all to ISO 8601 in the connector
• GetOwnedGames with include_played_free_games=1 returns free-to-play games too, which significantly inflates the game count vs. what users see in their Steam library

Friction

• Validator resolves schema paths as path.resolve(connectorDir, '..', 'schemas') — had to place schemas in connectors/schemas/ not connectors/valve/schemas/ for validation to pass. This was non-obvious.
• No existing API-key connectors in the registry to reference — all 8 existing connectors use browser automation. Had to infer the pattern from validator checks.

What worked well

• Steam Web API is stable, well-documented, and doesn't require OAuth — API key + Steam ID is all you need
• page.httpFetch() worked perfectly for all endpoints, no cookie/session complications
• Single iteration: connector passed validation (36/36 structure, 45/46 result) on first run