merge: integrate oss branch — budget gating, MCP back-channel, events, loopback-only bind

Key features from OSS branch:
- Budget gating: rolling per-provider spend caps with BUDGET_EXCEEDED task state
- Agent MCP back-channel: runners mint tokens; /mcp endpoint resolves them
- Chatbot MCP server at /chatbot/mcp (requires api_token in config)
- Event timeline: unified event stream replacing ad-hoc question/summary flows
- Loopback-only default bind (127.0.0.1:8484); external_bind_allowed=true to expose
- repository_url required on task creation (enforces traceability)
- Auto-checker: spawns verification task after each execution

Conflict resolutions:
- serve.go: keep cfg.Runners.XEnabled() conditional registration from main + agentRegistry from oss
- config.go: keep RunnersConfig from main + BudgetConfig/ExternalBindAllowed from oss
- server.go: handleStaticFiles (base-path rewrite) kept; deduplicated duplicate from both sides
- executor/claude.go: accepted oss deletion (ClaudeRunner replaced by ContainerRunner)
- container_test.go: added noopChannel + AgentChannel parameter to Run call

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/internal/storage/db_test.go b/internal/storage/db_test.go
index 0e67e02..4d744a4 100644
--- a/internal/storage/db_test.go
+++ b/internal/storage/db_test.go
@@ -309,6 +309,44 @@ func TestListTasks_WithLimit(t *testing.T) {
 	}
 }
 
+func TestSpendByProviderSince(t *testing.T) {
+	db := testDB(t)
+	now := time.Now().UTC()
+
+	tk := &task.Task{
+		ID: "spend-task", Name: "S", Agent: task.AgentConfig{Type: "claude", Instructions: "x"},
+		Priority: task.PriorityNormal, Retry: task.RetryConfig{MaxAttempts: 1, Backoff: "linear"},
+		Tags: []string{}, DependsOn: []string{}, State: task.StatePending, CreatedAt: now, UpdatedAt: now,
+	}
+	if err := db.CreateTask(tk); err != nil {
+		t.Fatal(err)
+	}
+
+	// Two recent claude execs, one recent gemini, one old claude (outside window).
+	execs := []*Execution{
+		{ID: "s1", TaskID: "spend-task", StartTime: now.Add(-1 * time.Hour), Status: "COMPLETED", CostUSD: 1.5, Agent: "claude"},
+		{ID: "s2", TaskID: "spend-task", StartTime: now.Add(-2 * time.Hour), Status: "COMPLETED", CostUSD: 2.0, Agent: "claude"},
+		{ID: "s3", TaskID: "spend-task", StartTime: now.Add(-30 * time.Minute), Status: "COMPLETED", CostUSD: 0.75, Agent: "gemini"},
+		{ID: "s4", TaskID: "spend-task", StartTime: now.Add(-10 * time.Hour), Status: "COMPLETED", CostUSD: 99, Agent: "claude"},
+	}
+	for _, e := range execs {
+		if err := db.CreateExecution(e); err != nil {
+			t.Fatalf("create exec %s: %v", e.ID, err)
+		}
+	}
+
+	spends, err := db.SpendByProviderSince(now.Add(-5 * time.Hour))
+	if err != nil {
+		t.Fatalf("SpendByProviderSince: %v", err)
+	}
+	if got := spends["claude"]; got != 3.5 {
+		t.Errorf("claude spend: want 3.5 (old $99 excluded), got %v", got)
+	}
+	if got := spends["gemini"]; got != 0.75 {
+		t.Errorf("gemini spend: want 0.75, got %v", got)
+	}
+}
+
 func TestCreateExecution_AndGet(t *testing.T) {
 	db := testDB(t)
 	now := time.Now().UTC().Truncate(time.Second)