Dispatch v0.5.0

v0.5.0 — self-updating, WebSocket, diffing, runner, auth

This is the first build that updates itself: future releases arrive via in-app update download instead of manual re-downloads (signed, verified with this release's key).

• WebSocket client: / URLs become live connections with an in/out frame log and a message composer instead of one-shot sends.
• Response diffing: compare a response against saved examples, history, or any other open tab — JSON value diffs with array-order handling, plain-line diffs otherwise.
• Collection runner: parallel iterations with isolated variable copies; save failed responses as examples; edit data rows inline.
• OAuth 2.0: real authorization-code sign-in window (incl. PKCE) in addition to client credentials and password grants.
• Snippets menu with canned pm recipes; per-profile environment defaults; history matches URL and method text.
• Arena trim after closing tabs keeps RSS honest about what it holds.

macOS: universal DMG for Apple Silicon + Intel (macOS 13+). Windows and Linux bundles below.