Fix bd doctor to respect custom database names from config.json

Fixes #197: bd doctor was hardcoded to look for beads.db and didn't
check config.json for custom database names like beady.db.

Now both checkDatabaseVersion() and checkIDFormat() check config.json
first before falling back to the canonical database name.

cmd/bd/doctor.go

@@ -14,6 +14,7 @@ import (
 	"github.com/fatih/color"
 	"github.com/spf13/cobra"
 	"github.com/steveyegge/beads"
+	"github.com/steveyegge/beads/internal/configfile"
 	"github.com/steveyegge/beads/internal/daemon"
 	_ "modernc.org/sqlite"
 )
@@ -191,7 +192,15 @@ func checkInstallation(path string) doctorCheck {
 
 func checkDatabaseVersion(path string) doctorCheck {
 	beadsDir := filepath.Join(path, ".beads")
-	dbPath := filepath.Join(beadsDir, beads.CanonicalDatabaseName)
+	
+	// Check config.json first for custom database name
+	var dbPath string
+	if cfg, err := configfile.Load(beadsDir); err == nil && cfg != nil && cfg.Database != "" {
+		dbPath = cfg.DatabasePath(beadsDir)
+	} else {
+		// Fall back to canonical database name
+		dbPath = filepath.Join(beadsDir, beads.CanonicalDatabaseName)
+	}
 
 	// Check if database file exists
 	if _, err := os.Stat(dbPath); os.IsNotExist(err) {
@@ -257,7 +266,15 @@ func checkDatabaseVersion(path string) doctorCheck {
 
 func checkIDFormat(path string) doctorCheck {
 	beadsDir := filepath.Join(path, ".beads")
-	dbPath := filepath.Join(beadsDir, beads.CanonicalDatabaseName)
+	
+	// Check config.json first for custom database name
+	var dbPath string
+	if cfg, err := configfile.Load(beadsDir); err == nil && cfg != nil && cfg.Database != "" {
+		dbPath = cfg.DatabasePath(beadsDir)
+	} else {
+		// Fall back to canonical database name
+		dbPath = filepath.Join(beadsDir, beads.CanonicalDatabaseName)
+	}
 
 	// Check if using JSONL-only mode
 	if _, err := os.Stat(dbPath); os.IsNotExist(err) {