feat(pgdb): export config discovery functions for display purposes

Add FindConfig, ParseURIConfig, and GetConfigFiles as exported functions
to allow callers to retrieve database configuration info without
establishing a connection. Useful for version/startup info display.

database/pgdb/pool.go

@@ -42,7 +42,7 @@ type PoolOptions struct {
 // DefaultPoolOptions returns sensible defaults for pgxpool
 func DefaultPoolOptions() PoolOptions {
 	return PoolOptions{
-		ConfigFiles:       getConfigFiles(),
+		ConfigFiles:       GetConfigFiles(),
 		MinConns:          0,
 		MaxConns:          25,
 		MaxConnLifetime:   time.Hour,
@@ -96,7 +96,7 @@ func OpenPool(ctx context.Context, options PoolOptions) (*pgxpool.Pool, error) {
 		}
 	} else {
 		// Fall back to config file approach
-		pgCfg, err := findAndParseConfig(options.ConfigFiles)
+		pgCfg, _, err := FindConfig(options.ConfigFiles)
 		if err != nil {
 			return nil, err
 		}
@@ -137,8 +137,15 @@ func OpenPoolWithConfigFile(ctx context.Context, configFile string) (*pgxpool.Po
 	return OpenPool(ctx, options)
 }
 
-// findAndParseConfig searches for and parses the first existing config file
-func findAndParseConfig(configFiles []string) (*database.PostgresConfig, error) {
+// FindConfig searches for and parses the first existing config file.
+// Returns the PostgresConfig, the path to the config file used, and any error.
+// If DATABASE_URI env var is set, returns nil config with empty path (use ParseURIConfig instead).
+func FindConfig(configFiles []string) (*database.PostgresConfig, string, error) {
+	// Check if DATABASE_URI takes precedence
+	if os.Getenv("DATABASE_URI") != "" {
+		return nil, "", nil
+	}
+
 	var errs []error
 	var triedFiles []string
 
@@ -161,13 +168,23 @@ func findAndParseConfig(configFiles []string) (*database.PostgresConfig, error)
 			continue
 		}
 
-		return pgCfg, nil
+		return pgCfg, configFile, nil
 	}
 
 	if len(errs) > 0 {
-		return nil, fmt.Errorf("no valid config file found (tried: %v): %w", triedFiles, errors.Join(errs...))
+		return nil, "", fmt.Errorf("no valid config file found (tried: %v): %w", triedFiles, errors.Join(errs...))
 	}
-	return nil, fmt.Errorf("no valid config files provided")
+	return nil, "", fmt.Errorf("no valid config files provided")
+}
+
+// ParseURIConfig extracts connection info from DATABASE_URI environment variable.
+// Returns nil if DATABASE_URI is not set.
+func ParseURIConfig() (*pgxpool.Config, error) {
+	uri := os.Getenv("DATABASE_URI")
+	if uri == "" {
+		return nil, nil
+	}
+	return pgxpool.ParseConfig(uri)
 }
 
 // parseConfigFile reads and parses a YAML config file
@@ -205,8 +222,9 @@ func parseConfigFile(configFile string) (*database.PostgresConfig, error) {
 	return nil, fmt.Errorf("no PostgreSQL configuration found in %s", configFile)
 }
 
-// getConfigFiles returns the list of config files to search
-func getConfigFiles() []string {
+// GetConfigFiles returns the list of config files to search for database configuration.
+// Checks DATABASE_CONFIG_FILE env var first, otherwise returns default paths.
+func GetConfigFiles() []string {
 	if configFile := os.Getenv("DATABASE_CONFIG_FILE"); configFile != "" {
 		return []string{configFile}
 	}