refactor(mcp): standardize telemetry server and consolidate query tools

[victoriacheng15]

Summary

Standardized the mcp-telemetry server with a graceful shutdown pattern and consolidated telemetry query tools into a unified structure. These updates enhance platform resilience by ensuring deterministic resource cleanup and simplify the security audit surface for telemetry data access.

List of Changes

• Operational Resilience: Implemented signal-based lifecycle management to ensure reliable telemetry flushing and connection draining during server termination, preventing data gaps during deployments.
• Architectural Maintainability: Consolidated fragmented query handlers into a unified domain logic layer. This reduces technical debt by centralizing security validation (dangerous pattern detection) and providing a single, consistent interface for all telemetry signals.

Verification

• Ran go test -v ./internal/mcp/tools/...