chore: fix local plugin builds & docs (#1851)

Raised by [MitchellThompkins](https://github.com/MitchellThompkins) in
#1848

- Documents how to use Docker to build a local Connect plugin
- Local Plugin flow will now build workspace packages before proceeding
with plugin infra + build
- Removes recommendation to run `pnpm build:watch` from root, as this
race conditions and build cache issues.
- Makes `pnpm dev` from root parallel, preventing servers from blocking
each other.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Documentation**
* Updated development workflow documentation to emphasize Docker-based
plugin builds
* Restructured development modes into three workflows: local Docker
builds, direct deployment, and development servers
  * Updated build and deployment instructions

* **Chores**
  * Modified dev script for parallel execution
  * Refactored build scripts with improved dependency handling

<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

readme.md

@@ -210,22 +210,34 @@ Once you have your key pair, add your public SSH key to your Unraid server:
 
 ### Development Modes
 
-The project supports two development modes:
+#### Mode 1: Local Plugin Build (Docker)
 
-#### Mode 1: Build Watcher with Local Plugin
-
-This mode builds the plugin continuously and serves it locally for installation on your Unraid server:
+Build and test a full plugin locally using Docker:
 
 ```sh
-# From the root directory (api/)
-pnpm build:watch
+cd plugin
+pnpm run docker:build-and-run
+# Then inside the container:
+pnpm build
 ```
 
-This command will output a local plugin URL that you can install on your Unraid server by navigating to Plugins → Install Plugin. Be aware it will take a *while* to build the first time.
+This builds all dependencies (API, web), starts a Docker container, and serves the plugin at `http://YOUR_IP:5858/`. Install it on your Unraid server via Plugins → Install Plugin.
 
-#### Mode 2: Development Servers
+#### Mode 2: Direct Deployment
 
-For active development with hot-reload:
+Deploy individual packages directly to an Unraid server for faster iteration:
+
+```sh
+# Deploy API changes
+cd api && pnpm unraid:deploy <SERVER_IP>
+
+# Deploy web changes
+cd web && pnpm unraid:deploy <SERVER_IP>
+```
+
+#### Mode 3: Development Servers
+
+For active development with hot-reload (no Unraid server needed):
 
 ```sh
 # From the root directory - runs all dev servers concurrently
@@ -238,22 +250,11 @@ Or run individual development servers:
 # API server (GraphQL backend at http://localhost:3001)
 cd api && pnpm dev
 
-# Web interface (Nuxt frontend at http://localhost:3000) 
+# Web interface (Nuxt frontend at http://localhost:3000)
 cd web && pnpm dev
 ```
 
-### Building the Full Plugin
-
-To build the complete plugin package (.plg file):
-
-```sh
-# From the root directory (api/)
-pnpm build:plugin
-
-# The plugin will be created in plugin/dynamix.unraid.net.plg
-```
-
-To deploy the plugin to your Unraid server:
+### Deploying to Unraid
 
 ```sh
 # Replace SERVER_IP with your Unraid server's IP address