feat: add storage system with local disk and S3 providers

Introduces a provider-agnostic storage subsystem for file attachments.
Includes local disk and S3 backends, asset/attachment DB schemas, issue
attachment CRUD routes with multer upload, CLI configure/doctor/env
integration, and enriched issue ancestors with project/goal resolution.

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

cli/src/config/schema.ts

@@ -5,6 +5,9 @@ export {
   databaseConfigSchema,
   loggingConfigSchema,
   serverConfigSchema,
+  storageConfigSchema,
+  storageLocalDiskConfigSchema,
+  storageS3ConfigSchema,
   secretsConfigSchema,
   secretsLocalEncryptedConfigSchema,
   type PaperclipConfig,
@@ -12,6 +15,9 @@ export {
   type DatabaseConfig,
   type LoggingConfig,
   type ServerConfig,
+  type StorageConfig,
+  type StorageLocalDiskConfig,
+  type StorageS3Config,
   type SecretsConfig,
   type SecretsLocalEncryptedConfig,
   type ConfigMeta,