feat: migrate to docker-compose with selfhosted-supabase-mcp

- Replace legacy directory structure (api/, db/, functions/, logs/, pooler/) with
  single docker-compose.yml based self-hosted setup
- Add selfhosted-supabase-mcp TypeScript MCP server for database management
- Add .dockerignore for Docker build context
- Update .gitignore to exclude .env files, volumes/, backups, logs

selfhosted-supabase-mcp/src/tools/get_project_url.ts

@@ -0,0 +1,33 @@
+import { z } from 'zod';
+import type { SelfhostedSupabaseClient } from '../client/index.js';
+import type { ToolContext } from './types.js';
+
+// Input schema (none needed)
+const GetProjectUrlInputSchema = z.object({});
+type GetProjectUrlInput = z.infer<typeof GetProjectUrlInputSchema>;
+
+// Output schema
+const GetProjectUrlOutputSchema = z.object({
+    project_url: z.string().url(),
+});
+
+// Static JSON Schema for MCP capabilities
+const mcpInputSchema = {
+    type: 'object',
+    properties: {},
+    required: [],
+};
+
+// The tool definition
+export const getProjectUrlTool = {
+    name: 'get_project_url',
+    description: 'Returns the configured Supabase project URL for this server.',
+    inputSchema: GetProjectUrlInputSchema,
+    mcpInputSchema: mcpInputSchema, // Add static JSON schema
+    outputSchema: GetProjectUrlOutputSchema,
+    execute: async (input: GetProjectUrlInput, context: ToolContext) => {
+        const client = context.selfhostedClient;
+        const url = client.getSupabaseUrl(); // Use getter from client
+        return { project_url: url };
+    },
+};