refactor(file-input): extract storage providers into modular plugin packages

[OrangeGEProton]

Refactor file-input to Support Modular Provider Plugins

Closes #13

Problem

Storage providers (MongoDB, SQLite, Azure, S3) were hardcoded inside @startupjs-ui/file-input with if/else dynamic imports. SDK dependencies were listed as optional peers with "*" versions — leading to manual installs, version drift, and no extensibility.

Solution

Introduced a plugin registry pattern:

• providers/registry.js — central registerProvider(name, provider) / getProvider(name) API
• 4 separate plugin packages, each with pinned SDK versions:
  • @startupjs-ui/file-input-provider-mongo (mongodb@^6.12.0)
  • @startupjs-ui/file-input-provider-sqlite (built-in)
  • @startupjs-ui/file-input-provider-azure (@azure/storage-blob@^12.26.0)
  • @startupjs-ui/file-input-provider-s3 (@aws-sdk/client-s3@^3.600.0)

How it works

// Simply importing the package auto-registers the provider:
import '@startupjs-ui/file-input-provider-mongo'

The core providers/index.js resolves providers from the registry at runtime — no hardcoded imports.

Changes

File / Package	Change
packages/file-input/providers/registry.js	New — plugin registry module
packages/file-input/providers/index.js	Rewritten to use registry instead of hardcoded import()
packages/file-input/package.json	Removed optional peer deps (@aws-sdk/*, @azure/*, mongodb); added ./providers/registry export
packages/file-input/providers/{awsS3,azureblob,mongo,sqlite}.js	Deleted — replaced by plugin packages
packages/file-input-provider-{mongo,sqlite,azure,s3}/	New — 4 plugin packages
packages/file-input/README.mdx	Updated docs with plugin setup guide and custom provider API

Migration

# Before: manually install SDK with unknown version
- yarn add @azure/storage-blob

# After: install the plugin (SDK is bundled with a pinned version)
+ yarn add @startupjs-ui/file-input-provider-azure

# And import it in your server entry:
+ import '@startupjs-ui/file-input-provider-azure'

Checks

• ✅ yarn install — all packages linked via workspaces
• ✅ yarn eslint — no errors
• ✅ yarn tsc --noEmit --skipLibCheck — no errors