Rename OPENCODE_PASSWORD to OPENCODE_SERVER_PASSWORD for clearer authentication configuration

Improvements

• CoreFix HTTP exception handling order to prevent NamedError from masking HTTP exceptions
• CoreAdd password authentication and improve server security
• CoreImprove error handling for built-in plugin installation failures
• CoreAllow wildcard permissions to match both the command with and without arguments
• CoreFix model selection in title generation to use user's model instead of assistant's
• TerminalPrevent layout jump when toggling tips visibility in TUI@R44VC0RP
• TerminalAdd hint for variants toggle in TUI
• TerminalFix autocomplete reopening after backspace deletes space in terminal UI@Raviguntakala
• TerminalRename kvStore to store for consistency in TUI
• TerminalRedesign tips display on home screen
• TerminalRedesign tips display on home screen
• TerminalRemove update complete toast notification from TUI
• DesktopDisable AppImage build@Brendonovich
• DesktopImprove server detection and connection logic in desktop application@Brendonovich
• DesktopResolve defaultServerUrl inside AppInterface to improve server URL handling@Brendonovich