feat: add core modules (config, state, diff, apply, health)

config.py

@@ -0,0 +1,53 @@
+import os
+from dataclasses import dataclass
+
+
+HEADERS = {"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) Unraid-Sync/1.0"}
+
+
+@dataclass
+class Config:
+    ics_url: str
+    baikal_url: str
+    baikal_user: str
+    baikal_pass: str
+    sync_frequency: int
+
+
+def validate() -> Config:
+    errors = []
+
+    ics_url = os.environ.get("ICS_URL")
+    if not ics_url:
+        errors.append("ICS_URL is required")
+
+    baikal_url = os.environ.get("BAIKAL_URL")
+    if not baikal_url:
+        errors.append("BAIKAL_URL is required")
+
+    baikal_user = os.environ.get("BAIKAL_USER")
+    if not baikal_user:
+        errors.append("BAIKAL_USER is required")
+
+    baikal_pass = os.environ.get("BAIKAL_PASS")
+    if not baikal_pass:
+        errors.append("BAIKAL_PASS is required")
+
+    sync_freq_raw = os.environ.get("SYNC_FREQUENCY", "5")
+    try:
+        sync_frequency = int(sync_freq_raw)
+        if sync_frequency <= 0:
+            raise ValueError
+    except ValueError:
+        errors.append("SYNC_FREQUENCY must be a positive integer")
+
+    if errors:
+        raise ValueError("\n".join(errors))
+
+    return Config(
+        ics_url=ics_url,
+        baikal_url=baikal_url,
+        baikal_user=baikal_user,
+        baikal_pass=baikal_pass,
+        sync_frequency=sync_frequency,
+    )