crawlie v0.5.1

The desktop app got a glow-up, and crawlie finally learned some manners about what not to crawl.

Added

• JavaScript rendering, now in the desktop app. The --render superpower from 0.5.0 is a one-click toggle in the crawl settings, so you can audit React, Vue and Next sites without ever opening a terminal. (The CLI and MCP have had it all along.)
• Exclude hosts and paths, by plain text or regex. Tell crawlie what to skip (analytics domains, share links, endless faceted URLs) from the new Advanced settings, the CLI (--exclude-host, --exclude-path, plus their -regex cousins), or the crawl_site MCP tool. A bad regex fails fast instead of silently matching nothing.
• Global crawl defaults. Set your user agent, crawl budget, render mode and friends once in Settings, and every new crawl starts from there. Override per crawl whenever the mood strikes.
• Custom user agent, surfaced in the desktop Advanced settings (the CLI and MCP already had it).

Changed

• The desktop app looks like it is from this decade. A flat, Linear-style interface: a rounded content panel, a full-width sticky report header, a Pages table that finally uses the whole window, dark mode that moved into Settings and actually remembers your choice, and a Docs link in the sidebar.
• The Overview dashboard means something at a glance. Issues by category is a stacked severity bar, and Status codes and Crawl depth are colour-coded proportion strips instead of a row of identical grey bars.
• Default user agent is now crawlie (+https://crawlie.dev) (unversioned, and pointed at the right place).

Fixed

• Sidebar links open now. Docs, GitHub and the update Download links open in your default browser instead of quietly doing nothing inside the app.