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_app/tsconfig.json

@@ -0,0 +1,33 @@
+{
+	"$schema": "https://json.schemastore.org/tsconfig",
+	"extends": "../tsconfigs/frontend.json",
+	"compilerOptions": {
+		"target": "ES2023",
+		"lib": ["DOM", "DOM.Iterable", "ES2023"],
+		"moduleDetection": "force",
+		"verbatimModuleSyntax": true,
+		"allowArbitraryExtensions": true,
+		"sourceMap": true,
+		"noImplicitReturns": true,
+		"experimentalDecorators": true,
+		"emitDecoratorMetadata": true,
+		"downlevelIteration": true,
+		"paths": {
+			"@app/*": ["./src/*"],
+			"@app_scripts/*": ["./scripts/*"],
+			"@pkgs/*": ["./pkgs/*"],
+			"@fluxer/constants/src/*": ["./../packages/constants/src/*"],
+			"@fluxer/date_utils/src/*": ["./../packages/date_utils/src/*"],
+			"@fluxer/geo_utils/src/*": ["./../packages/geo_utils/src/*"],
+			"@fluxer/limits/src/*": ["./../packages/limits/src/*"],
+			"@fluxer/list_utils/src/*": ["./../packages/list_utils/src/*"],
+			"@fluxer/markdown_parser/src/*": ["./../packages/markdown_parser/src/*"],
+			"@fluxer/number_utils/src/*": ["./../packages/number_utils/src/*"],
+			"@fluxer/schema/src/*": ["./../packages/schema/src/*"],
+			"@fluxer/snowflake/src/*": ["./../packages/snowflake/src/*"],
+			"@fluxer/ui/src/*": ["./../packages/ui/src/*"]
+		}
+	},
+	"include": ["./src/**/*", "./scripts/**/*"],
+	"exclude": ["node_modules", "dist", "coverage"]
+}