dsh-tool-budget: DeepSeek Harness Session Tool Call Budget Control Plugin

`dsh-tool-budget` is a security plugin for DeepSeek Harness designed to prevent resource exhaustion caused by excessive tool calls in long sessions. It provides a hard-stop mechanism: when the number of calls in a single session exceeds a predefined threshold (default: 80), subsequent calls are blocked. The plugin excludes `job_*` tools by default. Users can adjust the limit value or exclusion rules through configuration files. Used together with `dsh-repeat-stop`, it effectively addresses repeated message flooding and total call count limit exceedance.