feat: [RM-1328]: Add Release Management toolset to default registry

[shashankJainHarness]

Description

• Migrate RMG tools from mcpInternal to registry-based mcpV2
• Enable release-management toolset by default (no longer opt-in)
• Add URL parsing and schema support for RMG resources

Test plan

• pnpm typecheck
• pnpm test (release-management, url-parser, structural-validation)
• Manual smoke test against RMG API (if applicable)

Type of Change

• Bug fix
• New feature
• Refactor
• Documentation
• Other

Checklist

• pnpm test passes
• pnpm typecheck passes
• pnpm build passes
• pnpm standards:check passes (architecture guardrails — see docs/coding-standards.md)
• pnpm docs:check passes (if registry/tool counts changed)

Coding Standards (registry-driven MCP model)

If this PR adds or changes Harness API coverage:

• No new server.registerTool() calls — only toolset definitions in src/registry/toolsets/
• Toolset registered in ALL_TOOLSETS and ToolsetName union
• operationPolicy on every new/changed endpoint
• Shared response extractors from src/registry/extractors.ts (no raw passthrough on real endpoints)
• identifierFields and scope declared on new resources
• No console.log() in src/ (stdio JSON-RPC safety)

[CLAassistant]

All committers have signed the CLA.