fix: paginate tool listing

[haosenwang1018]

Summary

• follow nextCursor when listing MCP tools
• return all tool pages before applying downstream filtering
• add a client unit test that covers paginated tool discovery

Problem

Issue #206 reports that mcp-cli silently drops tools from servers that paginate tools/list responses. The current client only requests the first page.

Fix

listTools() now keeps requesting tool pages until nextCursor is exhausted, then returns the full aggregated list. This makes list, grep, info, and the tool existence checks in call work correctly with paginated MCP servers.

Fixes #206

Validation

• git diff --check
• npx tsc --noEmit
• bun test tests/client.test.ts
• bun test tests/config.test.ts
• bun test tests/output.test.ts
• npx @biomejs/biome check src/client.ts tests/client.test.ts