feat: auto-detect project dependencies with AI agent integration

Add `openboot init` auto-detection: scans project files (package.json,
go.mod, Cargo.toml, docker-compose.yml, etc.) to detect missing
dependencies and install them via Homebrew.

Three modes designed for AI coding agents:
- `--check --json`: report missing deps as JSON (exit 1 if missing)
- `--auto`: auto-install all missing deps without prompts
- Interactive TUI for human users

Add `openboot setup-agent` command that writes global rules to
Claude Code and OpenAI Codex so agents automatically use openboot
when they encounter missing dependencies.

New package: internal/detector/ with 15 detection rules, version
extraction, docker-compose service parsing, and 25 unit tests.

Author: fullstackjam

internal/cli/init.go

@@ -1,6 +1,7 @@
 package cli
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -11,15 +12,37 @@ import (
 	"github.com/spf13/cobra"
 )
 
+var (
+	initCheck bool
+	initAuto  bool
+	initJSON  bool
+)
+
 var initCmd = &cobra.Command{
 	Use:   "init [directory]",
-	Short: "Set up project environment from .openboot.yml",
-	Long: `Read .openboot.yml from the project directory and install declared dependencies,
-run init scripts, and verify the environment is ready.`,
-	Example: `  # Initialize from current directory
+	Short: "Detect and install project dependencies",
+	Long: `Scan project files to detect required dependencies and install missing ones.
+
+Works without any config file — auto-detects from package.json, go.mod,
+Cargo.toml, docker-compose.yml, and 15+ other project file types.
+
+If .openboot.yml exists, uses that instead (explicit config takes priority).
+
+Designed for AI coding agents: run "openboot init --auto" before starting
+work on any project to ensure all dependencies are satisfied.`,
+	Example: `  # Auto-detect and interactively select (human mode)
   openboot init
 
-  # Initialize from specific directory
+  # Auto-install all missing dependencies (agent/CI mode)
+  openboot init --auto
+
+  # Check what's missing without installing (returns exit code 1 if missing)
+  openboot init --check
+
+  # JSON output for AI agents
+  openboot init --check --json
+
+  # Use explicit .openboot.yml config
   openboot init /path/to/project
 
   # Preview changes without installing
@@ -42,8 +65,18 @@ run init scripts, and verify the environment is ready.`,
 			return fmt.Errorf("directory does not exist: %s", absDir)
 		}
 
+		// If --check, --auto, or --json is used, go straight to auto-detect
+		if initCheck || initAuto || initJSON {
+			return runAutoDetect(absDir)
+		}
+
+		// Try .openboot.yml first
 		projectCfg, err := config.LoadProjectConfig(absDir)
 		if err != nil {
+			// .openboot.yml not found — fall back to auto-detection
+			if errors.Is(err, config.ErrConfigNotFound) {
+				return runAutoDetect(absDir)
+			}
 			return err
 		}
 
@@ -62,6 +95,9 @@ run init scripts, and verify the environment is ready.`,
 
 func init() {
 	initCmd.Flags().SortFlags = false
+	initCmd.Flags().BoolVar(&initCheck, "check", false, "check dependencies without installing (exit 1 if missing)")
+	initCmd.Flags().BoolVar(&initAuto, "auto", false, "auto-install all detected missing dependencies")
+	initCmd.Flags().BoolVar(&initJSON, "json", false, "output results as JSON (for AI agents and scripts)")
 	initCmd.Flags().BoolVar(&cfg.DryRun, "dry-run", false, "preview changes without installing")
 	initCmd.Flags().BoolVarP(&cfg.Silent, "silent", "s", false, "non-interactive mode (for CI/CD)")
 	initCmd.Flags().BoolVar(&cfg.Update, "update", false, "update Homebrew before installing")