feat(flutter-cursor-templates): introduce MCP integration and conventions in project brief

- Added optional MCP integration settings in project-brief.yaml, allowing for environment-based server configurations.
- Introduced conventions for strict package imports to enhance code organization and maintainability.
- Updated brief schema to validate new MCP properties and ensure correct usage.
- Implemented MCP JSON builder to generate .cursor/mcp.json based on project brief settings.
- Enhanced resolver to include MCP configuration in generated files when enabled.

This update improves integration capabilities and enforces coding standards across the project.

flutter-cursor-templates/templates/telemetry/gitignore.tmpl

@@ -0,0 +1,2 @@
+*.jsonl
+*.log

flutter-cursor-templates/templates/telemetry/log.sh.tmpl

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+# Append a JSONL usage line (local only). Requires jq when passing structured payload.
+set -euo pipefail
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+LOG="${ROOT}/telemetry/usage.jsonl"
+mkdir -p "$(dirname "$LOG")"
+echo "{\"ts\":\"$(date -u +%Y-%m-%dT%H:%M:%SZ)\",\"event\":\"${1:-note}\",\"detail\":\"${2:-}\"}" >>"$LOG"