Azure APIM + MCP Server Demo

<!--
    Rate Limiting Policy for MCP Server
    
    This policy demonstrates APIM's rate limiting capabilities:
    - Per-subscription rate limiting
    - Quota management
    - Burst protection
-->
<policies>
    <inbound>
        <base />
        
        <!-- Rate limit: 60 calls per minute per subscription -->
        <rate-limit-by-key 
            calls="60" 
            renewal-period="60" 
            counter-key="@(context.Subscription?.Key ?? context.Request.IpAddress)" 
            increment-condition="@(context.Response.StatusCode >= 200 && context.Response.StatusCode < 400)" />
        
        <!-- Daily quota: 1000 calls per subscription -->
        <quota-by-key 
            calls="1000" 
            renewal-period="86400" 
            counter-key="@(context.Subscription?.Key ?? context.Request.IpAddress)" />
        
    </inbound>
    
    <backend>
        <base />
    </backend>
    
    <outbound>
        <base />
        
        <!-- Add rate limit headers to response -->
        <set-header name="X-RateLimit-Limit" exists-action="override">
            <value>60</value>
        </set-header>
        <set-header name="X-RateLimit-Remaining" exists-action="override">
            <value>@(context.Variables.GetValueOrDefault<int>("remainingCalls", 60).ToString())</value>
        </set-header>
    </outbound>
    
    <on-error>
        <base />
    </on-error>
</policies>