feat: v3.1.0 — Live Platform Foundation (Track E.1-E.3)

Major release introducing the Live Platform architecture:

- SQLite database backend with async operations and migrations (E.1)
- AES-256-GCM credential encryption with HKDF key derivation (E.1)
- OAuth Social Login with GitHub and Google (E.2)
- Site management API with encrypted credential storage (E.3)
- Per-user MCP endpoints at /u/{user_id}/{alias}/mcp (E.3)
- User API keys with bcrypt hashing (E.3)
- Auto-generated config snippets for 5 MCP clients (E.3)
- Dashboard: dark/light mode, RBAC, My Sites, Connect page
- Active background health checks
- 452 tests (up from 303), all passing

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

core/config_snippets.py

@@ -0,0 +1,115 @@
+"""MCP client configuration snippet generation (Track E.3).
+
+Generates copy-paste configuration snippets for connecting AI clients
+(Claude Desktop, Claude Code, Cursor, VS Code, ChatGPT) to per-user
+MCP endpoints.
+
+Usage:
+    from core.config_snippets import generate_config, get_supported_clients
+
+    snippet = generate_config(
+        base_url="https://mcp.example.com",
+        user_id="abc123",
+        alias="myblog",
+        api_key="mhu_...",
+        client_type="claude_desktop",
+    )
+"""
+
+import json
+
+# Supported MCP client types
+SUPPORTED_CLIENTS = [
+    {
+        "id": "claude_desktop",
+        "label": "Claude Desktop",
+        "description": "Anthropic's desktop app for Claude",
+    },
+    {
+        "id": "claude_code",
+        "label": "Claude Code",
+        "description": "Anthropic's CLI for Claude",
+    },
+    {
+        "id": "cursor",
+        "label": "Cursor",
+        "description": "AI-first code editor",
+    },
+    {
+        "id": "vscode",
+        "label": "VS Code",
+        "description": "Visual Studio Code with MCP extension",
+    },
+    {
+        "id": "chatgpt",
+        "label": "ChatGPT",
+        "description": "OpenAI ChatGPT (URL-based)",
+    },
+]
+
+
+def get_supported_clients() -> list[dict[str, str]]:
+    """Return the list of supported MCP client types."""
+    return SUPPORTED_CLIENTS
+
+
+def generate_config(
+    base_url: str,
+    user_id: str,
+    alias: str,
+    api_key: str,
+    client_type: str,
+) -> str:
+    """Generate a configuration snippet for the given MCP client.
+
+    Args:
+        base_url: Public URL of the MCP Hub instance (no trailing slash).
+        user_id: User UUID.
+        alias: Site alias.
+        api_key: User API key (``mhu_...``).
+        client_type: One of the supported client type IDs.
+
+    Returns:
+        JSON configuration string ready for copy-paste.
+
+    Raises:
+        ValueError: If client_type is not supported.
+    """
+    base_url = base_url.rstrip("/")
+    endpoint_url = f"{base_url}/u/{user_id}/{alias}/mcp"
+    server_name = f"mcphub-{alias}"
+
+    if client_type in ("claude_desktop", "claude_code"):
+        config = {
+            "mcpServers": {
+                server_name: {
+                    "url": endpoint_url,
+                    "headers": {
+                        "Authorization": f"Bearer {api_key}",
+                    },
+                }
+            }
+        }
+        return json.dumps(config, indent=2)
+
+    elif client_type in ("cursor", "vscode"):
+        config = {
+            "mcp": {
+                "servers": {
+                    server_name: {
+                        "url": endpoint_url,
+                        "headers": {
+                            "Authorization": f"Bearer {api_key}",
+                        },
+                    }
+                }
+            }
+        }
+        return json.dumps(config, indent=2)
+
+    elif client_type == "chatgpt":
+        return endpoint_url
+
+    else:
+        valid = [c["id"] for c in SUPPORTED_CLIENTS]
+        raise ValueError(f"Unsupported client type '{client_type}'. Valid: {valid}")