docs: archive completed frame-bubbletea plan

Move frame-bubbletea design and plan to docs/plans/completed/ with
completion summary. Frame now implements tea.Model with full bubbletea
lifecycle.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/plans/completed/frame-bubbletea.md

@@ -0,0 +1,39 @@
+# Frame Bubbletea Upgrade — Completion Summary
+
+**Completed:** 22 February 2026
+**Module:** `forge.lthn.ai/core/cli`
+**Status:** Complete — Frame implements tea.Model with full bubbletea lifecycle
+
+## What Was Built
+
+Upgraded the Frame layout system from a static HLCRF renderer to a full
+bubbletea `tea.Model` with lifecycle management, keyboard handling, and
+panel navigation.
+
+### Key changes
+
+- **Frame implements `tea.Model`** — `Init()`, `Update()`, `View()` lifecycle
+- **`KeyMap`** — configurable keybindings with default set (quit, navigate,
+  help, focus cycling)
+- **`Navigate(name)` / `Back()`** — panel switching with history stack
+- **Focus management** — Tab/Shift-Tab cycles focus between visible models
+- **lipgloss layout** — HLCRF regions (Header, Left, Content, Right, Footer)
+  rendered with lipgloss instead of raw ANSI
+- **`FrameModel` interface** — models register with `Frame.Header()`,
+  `.Content()`, `.Footer()` etc., receiving focus/blur/resize messages
+
+### Tests
+
+Navigate/Back stack tests, focus cycling, key dispatch, resize propagation.
+All passing with `-race`.
+
+### Dependencies
+
+- `github.com/charmbracelet/bubbletea`
+- `github.com/charmbracelet/lipgloss`
+
+### Consumer
+
+`go-blockchain/cmd/chain/` is the first consumer — TUI dashboard uses
+Frame with StatusModel (header), ExplorerModel (content), KeyHintsModel
+(footer).