chore: fix build dependencies and frontend config

Migrate Docker SDK from github.com/docker/docker (+incompatible)
to github.com/moby/moby/client v0.3.0 + moby/moby/api v1.54.0
(proper Go modules). Adapt all container/image/network operations
to the new moby API (Filters, ContainerListOptions, PullResponse,
InspectResult, etc.). Add AsyncTriggerDeploy runDeploy method.

Fix SvelteKit build: disable prerender, set strict=false for SPA,
bump vite-plugin-svelte to v5 for vite 6 compat.

Add .dockerignore to exclude .git, node_modules, plans.

internal/docker/client.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"fmt"
 
-	"github.com/docker/docker/client"
+	"github.com/moby/moby/client"
 )
 
 // Labels applied to all containers managed by docker-watcher.
@@ -42,7 +42,7 @@ func (c *Client) Close() error {
 
 // Ping checks connectivity to the Docker daemon.
 func (c *Client) Ping(ctx context.Context) error {
-	_, err := c.api.Ping(ctx)
+	_, err := c.api.Ping(ctx, client.PingOptions{})
 	if err != nil {
 		return fmt.Errorf("ping docker daemon: %w", err)
 	}