feat(executor): budget-gate the dispatcher — reroute to local or block (Phase 6)

The pool now consults a BudgetGate before taking an agent slot. If running on
the chosen paid provider could breach its rolling window (estimated by the
task's max_budget_usd), it reroutes to the free local runner when one is
registered; otherwise it stops before running and marks the task
BUDGET_EXCEEDED. serve.go builds a budget.Accountant from [budget] config and
wires it into the pool (only when limits are configured).

Allows the QUEUED → BUDGET_EXCEEDED transition, since the gate blocks a queued
task before it ever reaches RUNNING. Covered by pool tests for both the block
and reroute paths against a fake gate.

https://claude.ai/code/session_01SESwn7kQ7oP62trWw6pc39

1 files changed, 18 insertions, 0 deletions

diff --git a/internal/cli/serve.go b/internal/cli/serve.go
index e545763..55fdaf5 100644
--- a/internal/cli/serve.go
+++ b/internal/cli/serve.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/thepeterstone/claudomator/internal/api"
+	"github.com/thepeterstone/claudomator/internal/budget"
 	"github.com/thepeterstone/claudomator/internal/executor"
 	"github.com/thepeterstone/claudomator/internal/notify"
 	"github.com/thepeterstone/claudomator/internal/storage"
@@ -144,6 +145,23 @@ func serve(addr string) error {
 		pool.LLM = localClient
 	}
 
+	// Budget accountant: gate paid providers against rolling per-provider caps.
+	// With no limits configured this is created but allows everything.
+	var accountant *budget.Accountant
+	if len(cfg.Budget.Provider5hUSD) > 0 {
+		window := budget.DefaultWindow
+		if cfg.Budget.Window != "" {
+			if d, derr := time.ParseDuration(cfg.Budget.Window); derr == nil {
+				window = d
+			} else {
+				logger.Warn("invalid budget.window; using default", "value", cfg.Budget.Window, "default", window)
+			}
+		}
+		accountant = budget.New(store, budget.Limits{Window: window, PerProvider: cfg.Budget.Provider5hUSD})
+		pool.Budget = accountant
+		logger.Info("budget gating enabled", "window", window, "limits", cfg.Budget.Provider5hUSD)
+	}
+
 	if err := store.SeedProjects(); err != nil {
 		logger.Error("failed to seed projects", "error", err)
 	}