Cache lists and topics in session

[merefield]

Summary

• cache topic lists and topics in-session to reduce repeated fetches
• apply incoming topic updates incrementally via MessageBus topic ids
• load missing topic post chunks on demand and reduce polling/refetch churn

Verification

• ruby -c lib/termcourse/client.rb
• ruby -c lib/termcourse/live_updates.rb
• ruby -c lib/termcourse/ui.rb
• bin/test

[Copilot]

Pull request overview

This PR adds in-session caching for topic lists and individual topics, applies incremental updates from MessageBus for new/updated topics, and loads post chunks on demand instead of refetching entire topics. It also reduces polling frequency for PM and notification unread counts by introducing TTL-based refresh intervals.

Changes:

• Added @topic_list_cache and @topic_cache with incremental update support via MessageBus incoming topic IDs, replacing full refetches on each loop iteration
• Introduced on-demand post chunk loading (load_previous_topic_chunk/load_next_topic_chunk) and local state updates for likes, replies, and notification counts
• Added TTL-gated polling for PM and notification unread counts, falling back to live update counts when available

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
lib/termcourse/client.rb	Added params: keyword to list_topics, near_post: to topic, and new topic_posts/post endpoints
lib/termcourse/live_updates.rb	Added incoming_topic_ids and clear_incoming methods for incremental topic consumption
lib/termcourse/ui.rb	Core caching logic: list/topic caches, chunk loading, local like/reply state, TTL-based refresh, merge helpers
test/ui_caching_test.rb	Tests for caching, incremental refresh, chunk loading, and local state updates

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.