Tailoring: wire starship into .bashrc only when dotfiles are absent

Per YuKu: after the starship install, append
  export STARSHIP_CONFIG=$HOME/.config/starship.toml
  eval "$(starship init bash)"
to ~/.bashrc — but ONLY when fedora-dots was NOT cloned (on dots
machines .bashrc belongs to the dots). Also gated on starship actually
being present (no dead eval in every shell) and idempotent (grep
guard). Harness: appended once with dots=no, never with dots=yes
(clean-home re-test; the first test was invalid because rm -rf home/*
left the previous .bashrc — the known dotfile-cleanup pitfall), and
not duplicated on re-run.

setup.sh

@@ -606,6 +606,22 @@ if command -v starship >/dev/null 2>&1 && [[ ! -f "$HOME/.config/starship.toml"
     starship preset tokyo-night -o "$HOME/.config/starship.toml" \
         || warn "Could not apply the preset (starship still installed)."
 fi
+
+# bashrc wiring — ONLY when dotfiles were not cloned: on machines that
+# use fedora-dots, .bashrc is owned by the dots and must not be edited
+# here. Also requires starship to actually be present (a missing binary
+# would make every shell print an error from the eval line).
+if [[ "$DOTFILES" != "true" ]] \
+    && command -v starship >/dev/null 2>&1 \
+    && ! grep -q "starship init" "$HOME/.bashrc" 2>/dev/null; then
+    info "Wiring starship into ~/.bashrc..."
+    cat >> "$HOME/.bashrc" <<'EOF'
+
+# starship
+export STARSHIP_CONFIG="$HOME/.config/starship.toml"
+eval "$(starship init bash)"
+EOF
+fi
 pause_if_debug
 
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