Initial commit: Agentic OS troubleshooting platform

Self-hosted, Docker-based agentic troubleshooting platform: FastAPI backend +
LangGraph agent, Next.js UI, tiered LLM routing (local Ollama -> Gemini ->
DeepSeek -> OpenRouter), MCP server manager, encrypted device credentials,
RBAC, audit log, project-memory + Obsidian integrations, and editable
troubleshooting decision rules tuned for the GeneseasX vessel stack.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/models/audit.py

@@ -0,0 +1,27 @@
+"""Audit log of security-relevant actions."""
+from __future__ import annotations
+
+from datetime import datetime
+
+from sqlalchemy import DateTime, ForeignKey, Integer, String, func
+from sqlalchemy.dialects.postgresql import JSONB
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.database import Base
+
+
+class AuditLog(Base):
+    __tablename__ = "audit_logs"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    actor_id: Mapped[int | None] = mapped_column(
+        ForeignKey("users.id", ondelete="SET NULL"), nullable=True
+    )
+    actor_email: Mapped[str | None] = mapped_column(String(255), nullable=True)
+    action: Mapped[str] = mapped_column(String(128), index=True)
+    target_type: Mapped[str | None] = mapped_column(String(64), nullable=True)
+    target_id: Mapped[int | None] = mapped_column(Integer, nullable=True)
+    detail: Mapped[dict | None] = mapped_column(JSONB, nullable=True)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), server_default=func.now(), index=True
+    )