clet v1.0.0-rc.1

What's Changed

• ci: block stale Terminal.Gui pins by @tig in #164
• Refactor clet edit to use Editor chrome controls by @tig in #163
• Close threat model review gaps by @tig in #166
• ci: stop develop release dispatches by @tig in #169
• Move releases to main-only rc channel by @tig in #172
• Add hero GIF recording scripts and README demos by @tig in #173
• Make --prompt a global alias for --title across all clets by @Copilot in #175

Full Changelog: v1.0.0-alpha.6...v1.0.0-rc.1