chore(tui): delete the unused session footer component

DIVERGENCES.md

@@ -127,6 +127,7 @@ from the squash message first, or use a plain merge.
 | `packages/tui/src/component/spinner.tsx` | `SPINNER_FRAMES` swapped from cli-spinners "dots" (10 braille frames) to cli-spinners "sand" (35 braille frames, falling-sand animation); interval stays 80 ms | Fork visual identity for the shared `Spinner` component (in-progress tool/thinking rows, startup loading, session-list dialogs). | Keep our frames array; take upstream's surrounding changes. |
 | `packages/tui/src/component/prompt/index.tsx` | Busy footer spinner is cli-spinners "aesthetic" instead of the Knight Rider block scanner: module-level `FOOTER_FRAMES` (`▰▱` ramp, 7 chars, 8 frames), `spinnerDef` keeps the agent-color resolution but returns those frames plus a per-char color fn (`▰` → agent color, `▱` → `deriveInactiveColor(color, 0.3)`) instead of `createFrames`/`createColors` from `ui/spinner`, and the `<spinner>` interval is 120 ms (was 40; cli-spinners' stock 80 felt too fast). `ui/spinner.ts` itself is untouched; only its `deriveInactiveColor` import remains. | Fork visual identity for the busy indicator next to `esc interrupt`; the agent accent color still drives it. | Keep `FOOTER_FRAMES`, our `spinnerDef` body, the `deriveInactiveColor` import, and the 120 ms interval; take upstream's surrounding changes. If upstream reworks `spinnerDef`, re-apply the aesthetic frames + per-char color fn on top. |
 | `packages/tui/src/component/prompt/index.tsx`, `packages/tui/src/routes/session/index.tsx` | Compact prompt/footer spacing: the input box's interior `paddingTop={1}` is replaced by a height-1 half-block top-edge row above the box (`border={["top"]}`, `horizontal: "▄"` when `backgroundElement` is opaque, `" "` otherwise — mirror of the existing `"▀"` bottom-edge row; the agent/model meta row keeps its `paddingTop={1}`), and the session content container loses its `paddingBottom={1}` and its `gap={1}` (the gap fired between every pair of children — transcript↔prompt, and prompt↔the trailing flexGrow spacer, where it left a phantom blank row under the footer even at zero spacer height; the half-block lip is now the only transcript↔prompt separation) so the prompt footer line sits on the terminal's last row | The prompt box was a row taller than its content needed, a full blank row sat between the transcript and the box, and the footer floated 2 rows above the bottom edge; the half-block lip keeps a visible box edge above the text at half the height. | Keep the top-edge lip row and the padding/gap removals; take upstream's surrounding changes. If upstream restyles the box edges, re-apply the symmetric half-block lips and keep the container un-padded. |
+| `packages/tui/src/routes/session/footer.tsx` | Deleted. The file exported a `Footer` component (cwd, pending-permission count, LSP/MCP counts, `/status`) that nothing imports — it is dead upstream too, superseded there and here by the sidebar footer and the home footer. | Its contents live in `feature-plugins/sidebar/footer.tsx` (cwd:branch, editor-context label) and `feature-plugins/home/footer.tsx` (dir, MCP, `/status`, version); keeping an unreferenced third copy invites edits to a component that never renders. | Take upstream's version only if upstream starts importing it again; otherwise re-delete (`git rm`) after a sync reintroduces the file. |
 | `packages/tui/src/routes/session/question.tsx` | Selection/hover highlight color: a `highlight` memo (`tint(theme.backgroundPanel, theme.text, 0.1)`) replaces `theme.backgroundElement` on the active option row (number + label boxes, both the option list and the "Type your own answer" row) and on the question/Confirm tab hover state | `backgroundElement` sits ~1.04x off `backgroundPanel` in light themes (`#f5f5f5` on `#fafafa` for `codev`), so the selected answer had no visible highlight; blending the panel toward the theme's text color keeps a neutral band that is ~1.2x in both modes and works for generated/system themes too. | Keep the `highlight` memo and its four/two call sites; take upstream's surrounding changes. If upstream adds new `backgroundElement` highlights in this panel, point them at `highlight()` too. |
 | `packages/tui/src/app.tsx` | Mounted `<EditorLabelProvider>` (fork-only `./context/editor-label`) immediately inside `<EditorContextProvider>` | The effective-editor-selection state is shared by the prompt and the sidebar footer, so it has to be provided above both. | Keep the import and the wrapper; take upstream's surrounding provider changes. If upstream moves `EditorContextProvider`, keep ours directly inside it. |
 | `packages/app/index.html` | `<title>` → "CoDev Code" | Web UI tab title. | Keep our title. |