v4.3.1 — UI polish, telemetry worker

Rollup of 7 commits since v4.3.0. Brew users on the previous tag should run brew upgrade ccc to pick this up.

Fixed

• UI: render local-command stdout in the conversation pane (commands that emit text now show their output inline instead of going silent).
• UI: properly hide GH-issue cards in both the list view and the kanban when the hide-GH preference is on.

Added

• Inline SVG engine-source badges (Claude / Codex / Antigravity) in session headers.
• Opt-in anonymous telemetry: a daily ping lands on a Cloudflare Worker → D1 to help size the user base. Off by default. CCC_TELEMETRY_DISABLED=1 to kill at the env level. See docs/telemetry.md.
• README + landing-page: brew tap install path alongside the curl one-liner.
• v4 hero kanban screenshot (docs/images/kanban-v4.png) and refreshed social-preview.png.

Docs

• Competitor comparison matrix updated (removed defunct Chorus column, refined per-engine claims).