Migrate declarative configs to config/ dir and remove hardcoded paths

Replace all hardcoded /home/wall/vacuum-wall paths in lib/ with Path(__file__).resolve()
auto-discovery. Move config files from data/ to config/<subsystem>/config.json.
ACME now uses ACME_HOME env var and data/acme/ for cert storage. Systemd units
and sudoers use {{ USER_NAME }}, {{ PROJECT_DIR }}, {{ ACME_HOME }} Jinja2
template variables for install-time substitution. Remove sys.path.insert boot
strap from test files.

lib/wireguard.py

@@ -13,8 +13,8 @@ from pathlib import Path
 
 from jinja2 import Environment, FileSystemLoader
 
-PROJECT_DIR = Path("/home/wall/vacuum-wall")
-CONFIG_PATH = str(PROJECT_DIR / "data" / "wireguard" / "config.json")
+PROJECT_DIR = Path(__file__).resolve().parent.parent
+CONFIG_PATH = str(PROJECT_DIR / "config" / "wireguard" / "config.json")
 WG_CONF_PATH = "/etc/wireguard/wg0.conf"
 WG_QUICK_BIN = "wg-quick"
 WG_BIN = "wg"
@@ -141,7 +141,7 @@ def apply() -> None:
     conf_text = generate_conf(cfg)
     save_config(cfg)  # ensure latest state persisted
 
-    local_dir = Path("/home/wall/vacuum-wall/data/wireguard")
+    local_dir = PROJECT_DIR / "data" / "wireguard"
     local_dir.mkdir(parents=True, exist_ok=True)
     local_tmp = local_dir / "wg0.conf.tmp"
     with open(local_tmp, "w") as f: