refactor: move Python implementation to legacy/, make Go primary

Go (go/) becomes the primary implementation. The original Python
version moves to legacy/ and is kept runnable; new features are still
built in both (see the Dual implementation rule in CLAUDE.md).

- git mv app.py, scripts/, templates/, tests/, pyproject.toml, uv.lock
  and build/ into legacy/
- Makefile: Python targets point at legacy/, venv in legacy/.venv,
  CREDENTIALS_PATH exported for the root .secret/ file
- CI and make image build the Python image with legacy/ as context;
  the Makefile is no longer copied into the image
- legacy/.dockerignore moved to the context root so it takes effect
- CLAUDE.md, docs/README.md, Go comments, fixture README, capture
  script and VS Code launch config updated to the new layout

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

legacy/scripts/config.py

@@ -0,0 +1,52 @@
+"""Centralized configuration for FUJ management scripts.
+
+External service IDs, credentials, and tunable parameters.
+Domain-specific constants (fees, column indices) stay in their respective modules.
+"""
+
+import os
+from pathlib import Path
+
+# Paths
+PROJECT_ROOT = Path(__file__).parent.parent
+CREDENTIALS_PATH = Path(os.environ.get(
+    "CREDENTIALS_PATH",
+    str(PROJECT_ROOT / ".secret" / "fuj-management-bot-credentials.json"),
+))
+
+# Google Sheets IDs
+ATTENDANCE_SHEET_ID = "1E2e_gT_K5AwSRCDLDTa2UetZTkHmBOcz0kFbBUNUNBA"
+PAYMENTS_SHEET_ID = "1Om0YPoDVCH5cV8BrNz5LG5eR5MMU05ypQC7UMN1xn_Y"
+
+# Attendance sheet tab GIDs
+JUNIOR_SHEET_GID = "1213318614"
+
+# Bank accounts — hardcoded list mirroring go/internal/config/config.go.
+# The entry with primary=True is used for QR codes and as the BANK_ACCOUNT default.
+ACCOUNTS = [
+    {"iban": "CZ0820100000002502035405", "acct_num": "2502035405", "token_env": "FIO_API_TOKEN_NEW", "primary": True},
+    {"iban": "CZ8520100000002800359168", "acct_num": "2800359168", "token_env": "FIO_API_TOKEN_OLD", "primary": False},
+]
+# Resolve API tokens from the environment once at import time.
+LOADED_ACCOUNTS = [
+    {**a, "token": os.environ.get(a["token_env"], "")}
+    for a in ACCOUNTS
+]
+BANK_ACCOUNT = next(a["iban"] for a in ACCOUNTS if a["primary"])
+
+# Cache settings
+CACHE_DIR = PROJECT_ROOT / "tmp"
+DRIVE_TIMEOUT = 10  # seconds
+CACHE_TTL_SECONDS = int(os.environ.get("CACHE_TTL_SECONDS", 300))  # 5 min default
+CACHE_API_CHECK_TTL_SECONDS = int(os.environ.get("CACHE_API_CHECK_TTL_SECONDS", 300))  # 5 min default
+
+# Display settings
+MONTHS_TO_SHOW = int(os.environ.get("MONTHS_TO_SHOW", 5))  # show last N months; 0 = show all
+
+# Maps cache keys to their source sheet IDs (used by cache_utils)
+CACHE_SHEET_MAP = {
+    "attendance_regular": ATTENDANCE_SHEET_ID,
+    "attendance_juniors": ATTENDANCE_SHEET_ID,
+    "exceptions_dict": PAYMENTS_SHEET_ID,
+    "payments_transactions": PAYMENTS_SHEET_ID,
+}