[BUG] API Gateway GetUsagePlans ignores the keyId filter #7653

Service

API Gateway (REST APIs, v1)

AWS API Action

GetUsagePlans with its keyId query parameter (aws apigateway get-usage-plans --key-id <id>)

Expected behavior

API Gateway answers GET /usageplans?keyId=<id> with only the usage plans the key is added to. Measured on AWS (eu-west-1, AWS CLI 2.39.3) with two plans and a key added to the first:

Actual behavior

ApiGatewayController.getUsagePlans takes no keyId query parameter and answers every plan of the region, whatever the key. A key in no plan is reported as being in all of them.

A client that reads a key's plans before binding it then believes the key is already bound and skips CreateUsagePlanKey, so the key stays in no plan and every call with it on a method that requires a key answers 403. A client that moves a key between plans removes it from a plan it is not in and gets 404 NotFoundException Usage Plan Key not found from DeleteUsagePlanKey.

The docs state the gap: "Floci does not ... filter GetUsagePlans by keyId" (docs/services/api-gateway.md, "Usage plan stages, throttle and quota").

Reproduction

export AWS_ENDPOINT_URL=http://localhost:4566
A=$(aws apigateway create-usage-plan --name a --query id --output text)
B=$(aws apigateway create-usage-plan --name b --query id --output text)
K=$(aws apigateway create-api-key --name k --enabled --query id --output text)
aws apigateway get-usage-plans --key-id "$K" --query 'items[].name'
# AWS: []      Floci: ["a", "b"]
aws apigateway create-usage-plan-key --usage-plan-id "$A" --key-id "$K" --key-type API_KEY
aws apigateway get-usage-plans --key-id "$K" --query 'items[].name'
# AWS: ["a"]   Floci: ["a", "b"]

Environment

• Floci version / image tag: mariotoffia/floci:latest built from main at f9d3e906f; the code path is unchanged on main at cf96dad
• Java SDK version (if applicable): n/a
• How you're running Floci (Docker / native / mvn quarkus:dev): Docker