Ensure Codex built-in plugin is always available

Improvements

• CoreEnsure /connect works for OpenAI Business plans by adding missing field
• CoreTrack file modifications in ACP@wid4t
• CorePass sessionID to chat.system.transform@spoons-and-mirrors
• CoreExtract external directory validation to shared utility to reduce code duplication across tools
• CoreExclude 'none' variant for gpt-5.2-codex@Alejandro-CSt
• CoreFollow symlinks by default in ripgrep searches@kdcokenny
• CoreDisable telemetry in the PHP language server@madflow
• TerminalMove props.ref to onMount in TUI component@itsrainingmani
• TerminalFixed command palette incorrectly highlighting items on mouse hover@kitlangton
• DesktopAdd ability to fork sessions in desktop app@dbpolito
• DesktopMake mouse hover and click work on prompt input autocomplete@dbpolito
• DesktopAdd missing StoreExt import and fix unused mut warning in desktop@jerome-benoit
• DesktopFix missing import causing desktop build to fail@Leka74
• DesktopSupport configuring default server URL for desktop@athal7
• DesktopRemove split operation in serverDisplayName function@OpeOginni