Adds a URL input + Subscribe button (dx-components Input/Button) to the
UI, wired to a new subscribe_feed server function that upserts the feed
row and does an immediate first fetch so the reader isn't empty until
the next scheduled poll. feedsignal_feeds::fetch_feed now also returns
the feed's title, used to replace the URL placeholder once fetched.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XJJQb2DWZZwQ1yPiaAQQoY
Rust workspace with core (topic-affinity learning engine + relevance
scoring), db (sqlite/sqlx schema + repo), feeds (RSS/Atom fetch), llm
(rig + local Ollama embeddings/completion), and web (axum + Dioxus
fullstack UI, no separate JS stack). Two-stage relevance filtering
(embedding shortlist -> LLM judgment) and an engagement/surprise-based
topic affinity engine with daily decay. All crates compile and core's
affinity engine has passing unit tests; server and wasm client targets
of feedsignal-web both check clean.