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, 36 insertions, 0 deletions

diff --git a/internal/api/budget.go b/internal/api/budget.go
new file mode 100644
index 0000000..eee5d09
--- /dev/null
+++ b/internal/api/budget.go
@@ -0,0 +1,36 @@
+package api
+
+import (
+	"net/http"
+
+	"github.com/thepeterstone/claudomator/internal/budget"
+)
+
+// budgetReporter exposes per-provider spend headroom. Satisfied by
+// *budget.Accountant; an interface keeps the handler testable.
+type budgetReporter interface {
+	All() ([]budget.Headroom, error)
+}
+
+// SetBudget wires the budget accountant so GET /api/budget can report headroom.
+func (s *Server) SetBudget(b budgetReporter) {
+	s.budget = b
+}
+
+// handleGetBudget returns per-provider rolling-window spend headroom. When no
+// budget is configured it returns an empty list so the UI simply shows nothing.
+func (s *Server) handleGetBudget(w http.ResponseWriter, _ *http.Request) {
+	if s.budget == nil {
+		writeJSON(w, http.StatusOK, []budget.Headroom{})
+		return
+	}
+	hs, err := s.budget.All()
+	if err != nil {
+		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
+		return
+	}
+	if hs == nil {
+		hs = []budget.Headroom{}
+	}
+	writeJSON(w, http.StatusOK, hs)
+}