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>

packages/shared/src/index.ts

@@ -11,6 +11,7 @@ export {
   APPROVAL_TYPES,
   APPROVAL_STATUSES,
   SECRET_PROVIDERS,
+  STORAGE_PROVIDERS,
   HEARTBEAT_INVOCATION_SOURCES,
   HEARTBEAT_RUN_STATUSES,
   WAKEUP_TRIGGER_DETAILS,
@@ -28,6 +29,7 @@ export {
   type ApprovalType,
   type ApprovalStatus,
   type SecretProvider,
+  type StorageProvider,
   type HeartbeatInvocationSource,
   type HeartbeatRunStatus,
   type WakeupTriggerDetail,
@@ -44,6 +46,7 @@ export type {
   Project,
   Issue,
   IssueComment,
+  IssueAttachment,
   Goal,
   Approval,
   ApprovalComment,
@@ -94,11 +97,13 @@ export {
   checkoutIssueSchema,
   addIssueCommentSchema,
   linkIssueApprovalSchema,
+  createIssueAttachmentMetadataSchema,
   type CreateIssue,
   type UpdateIssue,
   type CheckoutIssue,
   type AddIssueComment,
   type LinkIssueApproval,
+  type CreateIssueAttachmentMetadata,
   createGoalSchema,
   updateGoalSchema,
   type CreateGoal,
@@ -139,12 +144,18 @@ export {
   loggingConfigSchema,
   serverConfigSchema,
   secretsConfigSchema,
+  storageConfigSchema,
+  storageLocalDiskConfigSchema,
+  storageS3ConfigSchema,
   secretsLocalEncryptedConfigSchema,
   type PaperclipConfig,
   type LlmConfig,
   type DatabaseConfig,
   type LoggingConfig,
   type ServerConfig,
+  type StorageConfig,
+  type StorageLocalDiskConfig,
+  type StorageS3Config,
   type SecretsConfig,
   type SecretsLocalEncryptedConfig,
   type ConfigMeta,