governance: keep repository root clean; remove marker file; implement repo detection via structure heuristic; update tests and system prompts/templates

tests/01_new_mode.sh

@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+set -euo pipefail
+ROOT_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+
+cd "$ROOT_DIR"
+
+mode="DemoMode"
+dir="modes/$mode"
+
+# Clean up from prior runs
+rm -rf "$dir"
+
+# Create new mode
+if ! bash ./CodexHelper new-mode --name "$mode" >nm.out 2>nm.err; then
+  echo "new-mode failed unexpectedly" >&2; exit 1
+fi
+
+[ -f "$dir/mode.md" ] || { echo "missing $dir/mode.md" >&2; exit 1; }
+[ -f "$dir/defaults.yaml" ] || { echo "missing $dir/defaults.yaml" >&2; exit 1; }
+
+# Running again without --force should fail
+if bash ./CodexHelper new-mode --name "$mode" >nm2.out 2>nm2.err; then
+  echo "new-mode should have failed on overwrite without --force" >&2; exit 1
+fi
+grep -qi "already exists" nm2.err || { echo "missing overwrite message" >&2; exit 1; }
+
+# With --force should succeed
+if ! bash ./CodexHelper new-mode --name "$mode" --force >nm3.out 2>nm3.err; then
+  echo "new-mode --force failed unexpectedly" >&2; exit 1
+fi
+
+exit 0
+