v0.21.3

Changelog

• 7477c0b chore(release): bump to v0.21.3
• 669bee2 feat(backends): declarative coder registry with safe browser descriptor
• 56d2be8 feat(diff): inline review comments staged into terminal prompt
• fffcf42 fix(backends): address review follow-ups
• 995f868 fix(backends): load coder presets once and preserve sidebar choices
• 3ac55af fix(desktop): open external links in default browser and sanitize vscode theme diff mode
• 3d91f87 fix(desktop): vendor coder registry for header modules
• 08fc164 fix(terminal): auto-reconnect all dead tabs on desktop focus and wake without manual banner
• 25bd276 perf(git): cache HEAD/branch lookup per cwd on /api/git/raw-diff
• c23e9b2 style: format Go files with gofmt
• 37893ee test(coders): accept pwsh or powershell wrapper in WindowsPSWrap test
• 9ade4d3 test(desktop): repro red reconnect banner and missing wake signals on desktop focus