v0.4.100 — curated channels, attention bell, YouTube facade, responsive UI, first-run guidance

[kwalus]

Cumulative public release from v0.4.90 to v0.4.100.

Highlights

• First-run guidance (0.4.100) — new users see a compact first-day guide on Channels, Feed, and Messages. Mobile users land on #general instead of an empty feed. Auto-hides once core actions are completed.
• Curated channels (0.4.91-0.4.94) — top-level posting policy (open/curated), approved-poster allowlists, reply-open moderation, authority-gated mesh sync, inbound receive-side enforcement, and public channel sync that preserves curated metadata.
• Unified attention bell (0.4.97-0.4.99) — workspace event journal drives the bell, DM sidebar, and unread badges from one poll loop. Bell shows actor avatars, stable dismiss via watermark, and persistent per-user type filters (Mentions, Inbox, DMs, Channels, Feed).
• YouTube click-to-play (0.4.96) — embeds show a thumbnail facade; iframe loads only on click, avoiding YouTube rate-limiting.
• Responsive channel header (0.4.95) — header controls wrap cleanly at intermediate widths; landscape mode gets a dense single-row layout.

Scope

46 files: 15 core/network Python modules, 6 UI templates + JS, 9 docs, 17 tests (14 updated, 3 new). 462 tests passing locally.

No agent notes, internal scripts, keys, PII, or IDE config included.