add edoxid calendar sync dag

Sync jadwal sidang eDOXID ke Google Calendar "Jadwal Sidang" tiap 5 menit
(read-only ke doxid2022), plus reminder email H-1/1-jam via Gmail API
karena reminder Calendar bawaan tidak ikut ke kalender pribadi attendee.

scripts/edoxid_calendar_state_store.py

@@ -0,0 +1,98 @@
+import hashlib
+import json
+import sqlite3
+from datetime import datetime
+
+
+class StateStore:
+    """State lokal (SQLite) tracking submission_id -> event_id + content_hash.
+    Sengaja TIDAK di doxid2022 — kalau file ini hilang/reset, paling buruk
+    event lama ke-recreate di Calendar, tidak merusak apa pun di DB eDOXID."""
+
+    def __init__(self, path: str):
+        self._conn = sqlite3.connect(path)
+        self._conn.execute(
+            """
+            CREATE TABLE IF NOT EXISTS sync_state (
+                submission_id INTEGER PRIMARY KEY,
+                event_id TEXT NOT NULL,
+                content_hash TEXT NOT NULL,
+                updated_at TEXT NOT NULL,
+                notified_h1 INTEGER NOT NULL DEFAULT 0,
+                notified_1h INTEGER NOT NULL DEFAULT 0
+            )
+            """
+        )
+        self._conn.commit()
+
+    def close(self) -> None:
+        self._conn.close()
+
+    @staticmethod
+    def compute_hash(submission: dict) -> str:
+        payload = json.dumps(
+            [
+                str(submission["schedule"]),
+                submission["room"],
+                submission["title"],
+                submission["type_id"],
+                submission["student_email"],
+                submission["student_nim"],
+                submission["verificators"],
+            ],
+            sort_keys=True,
+            default=str,
+        )
+        return hashlib.sha256(payload.encode("utf-8")).hexdigest()
+
+    def find(self, submission_id: int) -> dict | None:
+        row = self._conn.execute(
+            "SELECT event_id, content_hash FROM sync_state WHERE submission_id = ?",
+            (submission_id,),
+        ).fetchone()
+        if row is None:
+            return None
+        return {"event_id": row[0], "content_hash": row[1]}
+
+    def save(self, submission_id: int, event_id: str, content_hash: str) -> None:
+        self._conn.execute(
+            """
+            INSERT INTO sync_state (submission_id, event_id, content_hash, updated_at)
+            VALUES (?, ?, ?, ?)
+            """,
+            (submission_id, event_id, content_hash, datetime.utcnow().isoformat()),
+        )
+        self._conn.commit()
+
+    def update_hash(self, submission_id: int, content_hash: str) -> None:
+        self._conn.execute(
+            "UPDATE sync_state SET content_hash = ?, updated_at = ? WHERE submission_id = ?",
+            (content_hash, datetime.utcnow().isoformat(), submission_id),
+        )
+        self._conn.commit()
+
+    def remove(self, submission_id: int) -> None:
+        self._conn.execute("DELETE FROM sync_state WHERE submission_id = ?", (submission_id,))
+        self._conn.commit()
+
+    def is_notified(self, submission_id: int, which: str) -> bool:
+        column = "notified_h1" if which == "h1" else "notified_1h"
+        row = self._conn.execute(
+            f"SELECT {column} FROM sync_state WHERE submission_id = ?", (submission_id,)
+        ).fetchone()
+        return bool(row and row[0])
+
+    def mark_notified(self, submission_id: int, which: str) -> None:
+        column = "notified_h1" if which == "h1" else "notified_1h"
+        self._conn.execute(
+            f"UPDATE sync_state SET {column} = 1 WHERE submission_id = ?", (submission_id,)
+        )
+        self._conn.commit()
+
+    def find_orphaned(self, active_submission_ids: set[int]) -> dict[int, str]:
+        """Submission yang tercatat di state tapi schedule-nya sudah di-null-kan
+        (dibatalkan) atau baris submission-nya sudah dihapus — bukan sekadar
+        tanggalnya lewat. `active_submission_ids` harus dari query TANPA filter
+        tanggal (lihat Database.get_ids_with_active_schedule)."""
+        rows = self._conn.execute("SELECT submission_id, event_id FROM sync_state").fetchall()
+        return {sid: eid for sid, eid in rows if sid not in active_submission_ids}