fix(exec): use --output-format json to get structured output from claude

--json-schema combined with --output-format text produces empty stdout.
The structured result is in the "structured_output" field of the json
envelope. Updated executor to unwrap the envelope.

Also removes --bare flag which disables OAuth keychain reads, causing
silent auth failure when ANTHROPIC_API_KEY is not set.

Adds goreman Procfile + stdio bridge (cmd/bridge) for Claude Code MCP
integration. Task start/stop replaced with goreman + port-kill.

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

cmd/bridge/main.go

@@ -0,0 +1,59 @@
+// bridge is a stdio↔HTTP adapter that lets Claude Code connect to the
+// supervisor MCP server via the stdio transport.
+//
+// Claude Code spawns this binary as a subprocess and communicates over
+// stdin/stdout. Each newline-delimited JSON-RPC message from stdin is
+// forwarded to the supervisor HTTP server and the response is written back.
+//
+// Usage:
+//
+//	SUPERVISOR_URL=http://localhost:3200/mcp bridge
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+)
+
+func main() {
+	url := os.Getenv("SUPERVISOR_URL")
+	if url == "" {
+		url = "http://localhost:3200/mcp"
+	}
+
+	client := &http.Client{}
+	scanner := bufio.NewScanner(os.Stdin)
+	scanner.Buffer(make([]byte, 1024*1024), 1024*1024)
+
+	for scanner.Scan() {
+		line := scanner.Bytes()
+		if len(bytes.TrimSpace(line)) == 0 {
+			continue
+		}
+
+		req, err := http.NewRequest(http.MethodPost, url, bytes.NewReader(line))
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "bridge: build request: %v\n", err)
+			continue
+		}
+		req.Header.Set("Content-Type", "application/json")
+
+		resp, err := client.Do(req)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "bridge: request failed: %v\n", err)
+			continue
+		}
+		io.Copy(os.Stdout, resp.Body)
+		resp.Body.Close()
+		os.Stdout.Write([]byte("\n"))
+	}
+
+	if err := scanner.Err(); err != nil {
+		fmt.Fprintf(os.Stderr, "bridge: scanner: %v\n", err)
+		os.Exit(1)
+	}
+}