Whitelist terminal identity and pager env vars

Without TERM_PROGRAM/TERM_PROGRAM_VERSION, Claude Code and similar TUIs
can't detect the host emulator and lose capability-gated features like
Shift+Enter. Also pass through LS_COLORS, LESS*, MANPAGER, MANPATH, etc.
so interactive UX matches the host.

src/env.rs

@@ -36,19 +36,35 @@ const WHITELIST_KEEP_EXACT: &[&str] = &[
     "LOGNAME",
     "PATH",
     "SHELL",
+    "ZDOTDIR",
     // terminal
     "TERM",
+    "TERM_PROGRAM",
+    "TERM_PROGRAM_VERSION",
     "COLORTERM",
+    "COLORFGBG",
+    "LS_COLORS",
     "NO_COLOR",
     "FORCE_COLOR",
     "CLICOLOR",
     // locale
     "LANG",
+    "LANGUAGE",
     "TZ",
     // editor
     "EDITOR",
     "VISUAL",
     "PAGER",
+    // paging
+    "LESS",
+    "LESSOPEN",
+    "LESSCLOSE",
+    "LESSKEYIN",
+    "MANPAGER",
+    "SYSTEMD_PAGER",
+    // man / info
+    "MANPATH",
+    "INFOPATH",
     // tmp
     "TMPDIR",
     // proxy