Document language for dates; @eval pathname resolution and :cwd (from dev bc7cd62b6f68)

@date/@datetime gain :lang (German: "16. Juni 1910") over a document-wide
Language state variable, and :number for the numeric form (en 6/16/1910,
de 16.06.1910 per DIN 5008).  @eval finds Python modules next to the file
that names them regardless of the cwd, and the new :cwd option runs an
eval in a chosen working directory (@source_file uses it to resolve
against the document).  Two new test suites ship in tst/.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tst/modulepath_test.sh

@@ -0,0 +1,120 @@
+#!/bin/bash
+#
+# modulepath_test.sh — @eval pathname resolution (Klammermachine engine
+# tier): module resolution and the :cwd option.
+#
+# A Python module lives NEXT TO THE FILE whose @eval names it: the directory
+# of every file the Machine reads — input files, klammer sets, @read targets
+# — joins the Python sys.path (after the SKS directories), so resolution is
+# independent of the cwd.  Before 2026-07-27 modules were found only via
+# PYTHONPATH or the cwd, so `ktext /path/doc.kt` worked from the document's
+# directory and failed from anywhere else.
+#
+# The same directories are searched for a relative `:cpp` library not found
+# from the cwd (Eval::eval_command); that path is not exercised here because
+# it would mean compiling a DSO inside the test — the directory list is the
+# same one these cases prove.
+#
+# Pass-ordering caveat (deliberate, untested here): at one nesting level
+# @eval is processed before @read expands, so a TOP-LEVEL @eval sees only
+# files read earlier.  A klammer DEFINED in a read file is applied later and
+# always sees its own directory — the realistic case, tested below.
+#
+# Engine tier: -k none, fixtures created inline in a temp tree, no SKS.
+# Usage: ./modulepath_test.sh   (ktext on PATH)
+
+PASS=0
+FAIL=0
+
+red=$'\033[31m'
+green=$'\033[32m'
+bold=$'\033[1m'
+reset=$'\033[0m'
+
+T="$(mktemp -d)"
+trap 'rm -rf "$T"' EXIT
+
+mkdir -p "$T/seta" "$T/setb" "$T/elsewhere"
+printf 'def hello():\n    return "module-next-to-read-file"\n' > "$T/seta/pmod.py"
+printf '@@desc : @eval pmod.hello() @ @@#-\n' > "$T/seta/defs.k"
+printf 'def here():\n    return "module-next-to-input"\n' > "$T/setb/imod.py"
+printf '@read %s/seta/defs.k @#-@desc@ / @eval imod.here() @\n' "$T" > "$T/setb/doc.kt"
+printf '@eval nosuch_module_xyz.f() @\n' > "$T/setb/missing.kt"
+
+check() {   # check NAME EXPECTED ARGS...
+    local name="$1" expected="$2"; shift 2
+    local out
+    out=$(ktext "$@" -k none -d 2>/dev/null)
+    if [ "$out" = "$expected" ]; then
+        echo "${green}PASS${reset} $name"; PASS=$((PASS + 1))
+    else
+        echo "${red}FAIL${reset} $name"
+        echo "       expected: [$expected]"
+        echo "       got:      [$out]"; FAIL=$((FAIL + 1))
+    fi
+}
+
+echo "${bold}@eval module resolution tests${reset}"
+echo "======================="
+echo
+
+cd "$T/elsewhere"
+
+check " 1. modules beside the @read file and the input file (absolute path)" \
+      "module-next-to-read-file / module-next-to-input" \
+      "$T/setb/doc.kt"
+
+check " 2. the same, input given as a relative path" \
+      "module-next-to-read-file / module-next-to-input" \
+      "../setb/doc.kt"
+
+name=" 3. an unknown module still reports cleanly"
+err=$(ktext "$T/setb/missing.kt" -k none -d 2>&1 >/dev/null)
+case "$err" in
+    *'Cannot import module "nosuch_module_xyz"'*)
+        echo "${green}PASS${reset} $name"; PASS=$((PASS + 1)) ;;
+    *)
+        echo "${red}FAIL${reset} $name"
+        echo "       stderr: [$(echo "$err" | head -3)]"; FAIL=$((FAIL + 1)) ;;
+esac
+
+# --- the :cwd option --------------------------------------------------------
+# @eval :cwd DIR runs the eval (any mode) with DIR as the working directory
+# and restores the process cwd afterwards; *K_input_dir* names the
+# document's directory; whitespace-separated tokens are joined until they
+# name an existing directory (the filenames-with-spaces convention).
+
+printf 'hello from data file\n' > "$T/setb/data.txt"
+printf '@eval :cwd *K_input_dir* :shell cat data.txt @\n' > "$T/setb/shellcwd.kt"
+check " 4. :cwd *K_input_dir* for :shell, run from elsewhere" \
+      "hello from data file" "$T/setb/shellcwd.kt"
+
+printf '@eval :cwd *K_input_dir* os.getcwd() @\n' > "$T/setb/pycwd.kt"
+check " 5. :cwd changes the Python working directory" \
+      "$T/setb" "$T/setb/pycwd.kt"
+
+printf '@eval :cwd *K_input_dir* :shell true @ / @eval :shell pwd @\n' > "$T/setb/restore.kt"
+check " 6. the cwd is restored after the eval" \
+      "/ $T/elsewhere" "$T/setb/restore.kt"
+
+mkdir -p "$T/sp ace"
+printf 'spaced\n' > "$T/sp ace/f.txt"
+printf '@eval :cwd %s/sp ace :shell cat f.txt @\n' "$T" > "$T/setb/spaces.kt"
+check " 7. a :cwd directory containing spaces" \
+      "spaced" "$T/setb/spaces.kt"
+
+name=" 8. a nonexistent :cwd is a clean argument error"
+printf '@eval :cwd /nonexistent_kt_dir :shell true @\n' > "$T/setb/bad.kt"
+err=$(ktext "$T/setb/bad.kt" -k none -d 2>&1 >/dev/null)
+case "$err" in
+    *'The :cwd directory does not exist'*)
+        echo "${green}PASS${reset} $name"; PASS=$((PASS + 1)) ;;
+    *)
+        echo "${red}FAIL${reset} $name"
+        echo "       stderr: [$(echo "$err" | head -2)]"; FAIL=$((FAIL + 1)) ;;
+esac
+
+echo
+echo "======================="
+echo "Results: ${green}$PASS passed${reset}, ${red}$FAIL failed${reset}"
+[ $FAIL -eq 0 ]