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/prompts/storage.ts

@@ -0,0 +1,146 @@
+import * as p from "@clack/prompts";
+import type { StorageConfig } from "../config/schema.js";
+import { resolveDefaultStorageDir, resolvePaperclipInstanceId } from "../config/home.js";
+
+function defaultStorageBaseDir(): string {
+  return resolveDefaultStorageDir(resolvePaperclipInstanceId());
+}
+
+export function defaultStorageConfig(): StorageConfig {
+  return {
+    provider: "local_disk",
+    localDisk: {
+      baseDir: defaultStorageBaseDir(),
+    },
+    s3: {
+      bucket: "paperclip",
+      region: "us-east-1",
+      endpoint: undefined,
+      prefix: "",
+      forcePathStyle: false,
+    },
+  };
+}
+
+export async function promptStorage(current?: StorageConfig): Promise<StorageConfig> {
+  const base = current ?? defaultStorageConfig();
+
+  const provider = await p.select({
+    message: "Storage provider",
+    options: [
+      {
+        value: "local_disk" as const,
+        label: "Local disk (recommended)",
+        hint: "best for single-user local deployments",
+      },
+      {
+        value: "s3" as const,
+        label: "S3 compatible",
+        hint: "for cloud/object storage backends",
+      },
+    ],
+    initialValue: base.provider,
+  });
+
+  if (p.isCancel(provider)) {
+    p.cancel("Setup cancelled.");
+    process.exit(0);
+  }
+
+  if (provider === "local_disk") {
+    const baseDir = await p.text({
+      message: "Local storage base directory",
+      defaultValue: base.localDisk.baseDir || defaultStorageBaseDir(),
+      placeholder: defaultStorageBaseDir(),
+      validate: (value) => {
+        if (!value || value.trim().length === 0) return "Storage base directory is required";
+      },
+    });
+
+    if (p.isCancel(baseDir)) {
+      p.cancel("Setup cancelled.");
+      process.exit(0);
+    }
+
+    return {
+      provider: "local_disk",
+      localDisk: {
+        baseDir: baseDir.trim(),
+      },
+      s3: base.s3,
+    };
+  }
+
+  const bucket = await p.text({
+    message: "S3 bucket",
+    defaultValue: base.s3.bucket || "paperclip",
+    placeholder: "paperclip",
+    validate: (value) => {
+      if (!value || value.trim().length === 0) return "Bucket is required";
+    },
+  });
+
+  if (p.isCancel(bucket)) {
+    p.cancel("Setup cancelled.");
+    process.exit(0);
+  }
+
+  const region = await p.text({
+    message: "S3 region",
+    defaultValue: base.s3.region || "us-east-1",
+    placeholder: "us-east-1",
+    validate: (value) => {
+      if (!value || value.trim().length === 0) return "Region is required";
+    },
+  });
+
+  if (p.isCancel(region)) {
+    p.cancel("Setup cancelled.");
+    process.exit(0);
+  }
+
+  const endpoint = await p.text({
+    message: "S3 endpoint (optional for compatible backends)",
+    defaultValue: base.s3.endpoint ?? "",
+    placeholder: "https://s3.amazonaws.com",
+  });
+
+  if (p.isCancel(endpoint)) {
+    p.cancel("Setup cancelled.");
+    process.exit(0);
+  }
+
+  const prefix = await p.text({
+    message: "Object key prefix (optional)",
+    defaultValue: base.s3.prefix ?? "",
+    placeholder: "paperclip/",
+  });
+
+  if (p.isCancel(prefix)) {
+    p.cancel("Setup cancelled.");
+    process.exit(0);
+  }
+
+  const forcePathStyle = await p.confirm({
+    message: "Use S3 path-style URLs?",
+    initialValue: base.s3.forcePathStyle ?? false,
+  });
+
+  if (p.isCancel(forcePathStyle)) {
+    p.cancel("Setup cancelled.");
+    process.exit(0);
+  }
+
+  return {
+    provider: "s3",
+    localDisk: base.localDisk,
+    s3: {
+      bucket: bucket.trim(),
+      region: region.trim(),
+      endpoint: endpoint.trim() || undefined,
+      prefix: prefix.trim(),
+      forcePathStyle,
+    },
+  };
+}
+