MCP auth completes for manual servers; marketplace status fixed

Bug fixes

• Marketplace status reporting - A plugin marketplace that is working is no longer reported as missing
• Manually added MCP servers - MCP servers you add by hand can now finish authenticating instead of failing to connect (app)
• Thinking timer stability - The thinking timer keeps counting correctly when you move between views instead of restarting (app)
• Diff colors by theme - Added and removed lines in a diff now use the colors that match your light or dark theme (app)
• Paginated member pickers - Member pickers now page through everyone in your organization instead of showing only the first results (app)
• Markdown in default app - Markdown files now open in your default app instead of being blocked (app)