feat(executor,api): wire agent MCP into ContainerRunner + mount /mcp (Phase 2)

ContainerRunner now mints a per-task MCP token (from an injected Registry),
writes a claude mcp-config into the workspace pointing at the host agent MCP
server over host.docker.internal with that bearer, and adds --mcp-config to the
in-container claude invocation. The token is revoked when the run ends. After
the run, a buffered ask_user (PendingQuestion on the channel) is converted into
a BlockedError — the MCP path to BLOCKED — with the file-based question.json
kept as a fallback for in-flight tasks started on the old wire.

The API server mounts the StreamableHTTP MCP handler at POST/GET/DELETE /mcp
when a registry is provided; serve.go constructs one Registry shared by the
runners (mint) and the server (resolve). Minting is skipped for gemini agents.

Tests: writeMCPConfig output shape, buildInnerCmd flag presence/absence, and an
api-level end-to-end MCP tool call through NewServer/Handler proving the route
is mounted (and absent without a registry).

https://claude.ai/code/session_01SESwn7kQ7oP62trWw6pc39

1 files changed, 7 insertions, 1 deletions

diff --git a/internal/cli/serve.go b/internal/cli/serve.go
index 459c35b..b23304b 100644
--- a/internal/cli/serve.go
+++ b/internal/cli/serve.go
@@ -79,6 +79,9 @@ func serve(addr string) error {
 	claudeConfigDir := cfg.ClaudeConfigDir
 
 	repoDir, _ := os.Getwd()
+	// Shared per-task agent MCP token registry: runners mint tokens; the API
+	// server mounts /mcp and resolves them.
+	agentRegistry := executor.NewRegistry()
 	runners := map[string]executor.Runner{
 		// ContainerRunner: binaries are resolved via PATH inside the container image,
 		// so ClaudeBinary/GeminiBinary are left empty (host paths would not exist inside).
@@ -92,6 +95,7 @@ func serve(addr string) error {
 			ClaudeConfigDir:   claudeConfigDir,
 			CredentialSyncCmd: filepath.Join(repoDir, "scripts", "sync-credentials"),
 			Store:             store,
+			Registry:          agentRegistry,
 		},
 		"gemini": &executor.ContainerRunner{
 			Image:             cfg.GeminiImage,
@@ -103,6 +107,7 @@ func serve(addr string) error {
 			ClaudeConfigDir:   claudeConfigDir,
 			CredentialSyncCmd: filepath.Join(repoDir, "scripts", "sync-credentials"),
 			Store:             store,
+			Registry:          agentRegistry,
 		},
 		"container": &executor.ContainerRunner{
 			Image:             "claudomator-agent:latest",
@@ -114,6 +119,7 @@ func serve(addr string) error {
 			ClaudeConfigDir:   claudeConfigDir,
 			CredentialSyncCmd: filepath.Join(repoDir, "scripts", "sync-credentials"),
 			Store:             store,
+			Registry:          agentRegistry,
 		},
 	}
 
@@ -146,7 +152,7 @@ func serve(addr string) error {
 	pool.RecoverStaleQueued(context.Background())
 	pool.RecoverStaleBlocked()
 
-	srv := api.NewServer(store, pool, logger, cfg.ClaudeBinaryPath, cfg.GeminiBinaryPath)
+	srv := api.NewServer(store, pool, agentRegistry, logger, cfg.ClaudeBinaryPath, cfg.GeminiBinaryPath)
 
 	// Configure notifiers: combine webhook (if set) with web push.
 	notifiers := []notify.Notifier{}