Quorum v0.7.0

What's Changed

• Rebrand user-facing name: Quorum → Fletch by @alchaplinsky in #274
• Rebrand code sweep: Quorum → Fletch (comments, docs, internals) by @alchaplinsky in #275
• Rebrand follow-up: app icon, package rename & straggler by @alchaplinsky in #276
• Rebrand: domains → fletch.sh, delete dead QMark, tidy comments by @alchaplinsky in #277
• Rebrand: rename Cargo crate quorum → fletch by @alchaplinsky in #278
• feat(ui): header logo lockup — double-chevron mark + "fletch" wordmark by @alchaplinsky in #279
• rebrand: move worktree + RPC dirs to ~/.fletch by @alchaplinsky in #280
• rebrand: bundle id com.quorum.desktop → com.fletch.desktop by @alchaplinsky in #281
• rebrand: rename incidental quorum mentions in Rust test fixtures by @alchaplinsky in #282
• rebrand: replace app icon with new fletch mark by @alchaplinsky in #283

Full Changelog: v0.6.5...v0.7.0