fix(participation): trophy as the topic icon and paced post/pin in fresh topics

[TOMOKI977]

Summary

This PR fixes two problems in hackathon-participation that showed up in the production smoke test.

1. The trophy should be the topic icon, not part of its name

Topics were created with the name "🏆 BNB Hack: …" and the default icon.

• Adapter (src/adapters/telegram/forum-topic-manager.ts):
  • It resolves 🏆 through getForumTopicIconStickers() and matches the emoji field with U+FE0F stripped on both sides.
  • It creates the topic with icon_custom_emoji_id and a plain name.
  • It caches the icon list per isolate and clears the cache if the lookup fails.
  • If the list has no 🏆, or the lookup fails, it creates the topic with no icon and falls back to the name "🏆 ". The icon lookup can never make topic creation fail.
• Domain (src/domain/hackathon/topic.ts): topicNameFor(name, slug, iconApplied) returns either the plain name or the prefixed fallback, both within the 128-character cap. The General confirmation uses the plain name.

2. The pin in a freshly created topic was not applied

In production, pinChatMessage for the first post in a topic the bot had just created returned OK, but no pin and no "pinned a message" service message appeared. Pinning in a topic that already existed worked.

• participateInHackathon now paces the fresh-topic path only, through an injected sleep: create → link → wait 1500 ms (TOPIC_POST_DELAY_MS) → post → wait 1000 ms (PIN_DELAY_MS) → pin.
• The pin wait is passed to postAnalysisAndLinkTopic as pinDelayMs.
• The existing-topic check and the run-hackathon-job callers never wait.
• composition.ts wires the real setTimeout sleep. The callback is answered before the waits.

Review

A bounded review at medium risk ran the reliability lens over all 19 changed paths and found no severe findings.

Deferred warning R3-001: three e2e tests go through the real setTimeout sleep, adding about 2.5 s each against Vitest's default 5 s timeout. They could get flaky on a slow CI.

Tests

• Strict TDD.
• The full suite passes (1044 tests), and typecheck is clean.

🤖 Generated with Claude Code