Update AGENTS.md and scripts for global dependency installation

- Revise instructions in AGENTS.md to clarify that Python scripts should be run via `startup.sh`, which now installs dependencies globally.
- Enhance project overview and command sections for better clarity on usage.
- Update coding standards to reflect Python version requirements and Bash script practices.
- Improve formatting and organization of command examples for better readability.

startup.sh

@@ -1,69 +1,48 @@
 #!/usr/bin/env bash
 # -------------------------------------------------------------------
-# startup.sh  — prepare Python env, ensure deps & data, then run.
+# startup.sh  — install deps globally, fetch data, then run command
 # Usage:
-#   ./startup.sh [options]      # passes options to default plot script
-#   ./startup.sh [script or cmd] # runs specified script/command
+#   ./startup.sh [options]       # passes options to default plot script
+#   ./startup.sh <script> [args] # runs specified script with system Python
 # Examples:
 #   ./startup.sh --offset 12 --end 2025-05-31 --extend-years 5
 #   ./startup.sh pytest -q
 # -------------------------------------------------------------------
 set -euo pipefail
 
-VENV_DIR="venv"
 REQ_FILE="requirements.txt"
-WHEELHOUSE="wheelhouse"
 DATA_DB="data/fred.db"
-PYTHON="$VENV_DIR/bin/python"
 DEFAULT_SCRIPT="scripts/lagged_oil_unrate_chart_styled.py"
 
-# 1) Create or reuse venv
-if [[ ! -d "$VENV_DIR" ]]; then
-  echo "🔧 Creating virtual-env…"
-  python3 -m venv "$VENV_DIR"
-fi
-
-# 2) Activate venv
-# shellcheck disable=SC1090
-source "$VENV_DIR/bin/activate"
-
-# 3) Upgrade pip & setuptools
+# 1) Ensure pip & setuptools are up to date
 echo "🛠 Upgrading pip & setuptools…"
-$PYTHON -m pip install --upgrade pip setuptools
+pip install --upgrade pip setuptools
 
-# 4) Install dependencies
-PIP_OPTS=(install --upgrade --no-input)
-if [[ -d "$WHEELHOUSE" ]]; then
-  echo "📦 Installing from wheelhouse…"
-  $PYTHON -m pip "${PIP_OPTS[@]}" --no-index --find-links="$WHEELHOUSE" -r "$REQ_FILE" \
-    || { echo "⚠️ Wheelhouse failed—falling back…"; \
-         $PYTHON -m pip "${PIP_OPTS[@]}" -r "$REQ_FILE"; }
-else
-  echo "🌐 Installing from PyPI…"
-  $PYTHON -m pip "${PIP_OPTS[@]}" -r "$REQ_FILE"
-fi
+# 2) Install project dependencies globally
+echo "📦 Installing dependencies from $REQ_FILE…"
+pip install --upgrade -r "$REQ_FILE"
 
-echo "✅ Virtual-env ready ($($PYTHON -V))"
-
-# 5) Ensure data exists
+# 3) Ensure data exists
 if [[ ! -f "$DATA_DB" ]]; then
   echo "🔄 Data not found—downloading FRED series…"
-  $PYTHON scripts/refresh_data.py
+  python scripts/refresh_data.py
 fi
 
-# 6) Build command
+# 4) Dispatch to the right command
 if [[ $# -eq 0 ]]; then
-  CMD=("$PYTHON" "$DEFAULT_SCRIPT" --offset 18)
+  # no args → run default plot
+  CMD=(python "$DEFAULT_SCRIPT" --offset 18)
 elif [[ "$1" == --* ]]; then
-  CMD=("$PYTHON" "$DEFAULT_SCRIPT" "$@")
+  # args start with -- → forward to default plot
+  CMD=(python "$DEFAULT_SCRIPT" "$@")
 else
+  # first token is script or other command
   if [[ -f "$1" || "$1" == *.py ]]; then
-    CMD=("$PYTHON" "$@")
+    CMD=(python "$@")
   else
     CMD=("$@")
   fi
 fi
 
-# 7) Execute
 echo "🚀 Executing: ${CMD[*]}"
 exec "${CMD[@]}"