chore: V2 planning docs + template discovery

CHANGELOG.md

@@ -1,5 +1,30 @@
 # Changelog
 
+## [Unreleased] — V2 Planning Complete (2026-06-29)
+
+### Added (V2 Planning Documents)
+- `docs/v2/PROGRESS.md` — Status tracker for V2 development
+- `docs/v2/ARCHITECTURE.md` — System architecture (GoFiber + React + Electron)
+- `docs/v2/API.md` — REST API + WebSocket specification
+- `docs/v2/DATA_MODELS.md` — Extended data models (Groups, PortForward, Workspace)
+- `docs/v2/UI_COMPONENTS.md` — React component tree + state management
+- `docs/v2/UI_TERMIUS_REFERENCE.md` — Termius visual reference
+- `docs/v2/SPRINT_PLAN.md` — Sprint-by-sprint task breakdown
+- `docs/v2/BUILD_SYSTEM.md` — Cross-platform build pipeline
+- `docs/v2/PERFORMANCE.md` — Performance & stability guide
+
+### Architecture Decision
+- Backend: GoFiber v2 (fasthttp-based) replacing chi/net/http
+- WebSocket: gofiber/contrib/websocket (fasthttp/websocket) replacing gorilla/websocket
+- Frontend: React 19 + TypeScript + xterm.js + Zustand
+- Desktop: Electron (electron-builder)
+- Mobile: gomobile + WebView
+
+### V1 Status (FROZEN)
+- All V1 code (pkg/, internal/, cmd/, test/) is complete and frozen
+- V1 CLI/TUI remains functional alongside V2 GUI
+- 105 tests passing, zero race conditions
+
 ## [Unreleased] — 2025-01-31
 
 ### Fixed