feat: v2 admin UI overhaul, API tokens, branding, Swagger docs

Major changes:
- Fix all frontend-backend API contract mismatches (URLs, field names, methods)
- Add Bearer token auth (create/revoke tokens in admin, Authorization: Bearer ti_...)
- Add full branding system (logo upload, site name, accent color picker, markdown landing page)
- Add Swagger UI at /api/docs with complete OpenAPI 3.0 spec
- Add AutoDJ edit button, Studio mount selector, Go Live audio permission flow
- Add dashboard inbound+outbound bandwidth, GoLive headroom meters (dB)
- Fix streams page to show configured-but-offline mounts
- Remove CSRF requirement for JSON API requests
- Add proper markdown parser (marked) for landing page content
- Add go:generate for automatic frontend builds
- Add Makefile (make build, make quick, make dev)
- Update README with all new features, API examples, Bearer auth docs

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: syso

Makefile

@@ -0,0 +1,21 @@
+.PHONY: build generate dev clean
+
+# Full build: rebuild frontend + compile Go binary
+build: generate
+	go build -o tinyice .
+
+# Rebuild frontend assets via go generate
+generate:
+	go generate ./server/...
+
+# Quick build: Go only (skip frontend rebuild)
+quick:
+	go build -o tinyice .
+
+# Dev: run frontend dev server
+dev:
+	cd server/frontend && npm run dev
+
+clean:
+	rm -f tinyice
+	rm -rf server/frontend/dist