feat: add fluxer upstream source and self-hosting documentation

- Clone of github.com/fluxerapp/fluxer (official upstream)
- SELF_HOSTING.md: full VM rebuild procedure, architecture overview,
  service reference, step-by-step setup, troubleshooting, seattle reference
- dev/.env.example: all env vars with secrets redacted and generation instructions
- dev/livekit.yaml: LiveKit config template with placeholder keys
- fluxer-seattle/: existing seattle deployment setup scripts

fluxer/fluxer_server/package.json

@@ -0,0 +1,41 @@
+{
+	"name": "fluxer_server",
+	"version": "0.0.0",
+	"private": true,
+	"description": "Combined umbrella service for self-hosters bringing together all TypeScript backend services",
+	"license": "AGPL-3.0-or-later",
+	"type": "module",
+	"scripts": {
+		"dev": "tsx watch --clear-screen=false src/startServer.tsx",
+		"start": "tsx src/startServer.tsx",
+		"typecheck": "tsgo --noEmit"
+	},
+	"dependencies": {
+		"@fluxer/admin": "workspace:*",
+		"@fluxer/api": "workspace:*",
+		"@fluxer/app_proxy": "workspace:*",
+		"@fluxer/config": "workspace:*",
+		"@fluxer/constants": "workspace:*",
+		"@fluxer/errors": "workspace:*",
+		"@fluxer/hono": "workspace:*",
+		"@fluxer/hono_types": "workspace:*",
+		"@fluxer/initialization": "workspace:*",
+		"@fluxer/ip_utils": "workspace:*",
+		"@fluxer/kv_client": "workspace:*",
+		"@fluxer/logger": "workspace:*",
+		"@fluxer/media_proxy": "workspace:*",
+		"@fluxer/nats": "workspace:*",
+		"@fluxer/s3": "workspace:*",
+		"@fluxer/sentry": "workspace:*",
+		"hono": "catalog:",
+		"tsx": "catalog:"
+	},
+	"devDependencies": {
+		"@types/node": "catalog:",
+		"@typescript/native-preview": "catalog:"
+	},
+	"packageManager": "pnpm@10.29.3",
+	"engines": {
+		"node": ">=24.0.0"
+	}
+}