dsh-goal-budget: Set a budget for DSH goals, stop if exceeded

The workflow plugin maintained by boom-10 sets token, cost, and compute time limits for DSH long-running task goals. When limits are exceeded, it calls `ctx.goals.block()` to interrupt and disable auto-recovery, rather than merely displaying usage. The plugin attributes consumption based on `goalId` and `round` from session event logs, and the UI pill and blockage judgment share the same projection. It supports a two-layer configuration: temporary values set via `/budget` within the session and default values from the profile YAML. The installation commands, configuration fields, and known failure modes are all derived from the original README.