fix: strip ANSI from TUI test frames so FORCE_COLOR cannot break assertions (#2207)

Ink writes styling as escape sequences inside the styled run, so an
accelerator underline splits the word it decorates: `<Text underline>I</Text>nfo`
reaches the frame buffer with escapes between `I` and `nfo`, and a plain
`toContain("Info")` fails against a component that is rendering correctly.
Chalk only emits color when it detects a TTY, so CI stays green and the six
failures land only on a developer whose shell exports FORCE_COLOR.

Add `__tests__/helpers/renderTui.tsx` — ink-testing-library's `render` with
`lastFrame()` and `frames` ANSI-stripped — and point all 16 renderer test
files at it. `frames` is a getter reading through to the live array, since
Ink appends to it as the component re-renders; the raw bytes stay reachable
as `stdout.lastFrame()`.

Pinning FORCE_COLOR=0 would turn the six green while hiding the class: any
future assertion on styled text has the same problem, and the suite would
stop covering the styled path at all.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MFp2LVH7UJST5i8bDBJghw
Signed-off-by: cliffhall <cliff@futurescale.com>

AGENTS.md

@@ -386,6 +386,7 @@ diagnose a failing gate — is the `testing` skill. These are the rules.
   - **`clients/web`**: `<Name>.test.tsx` **next to the source** — components, hooks, `lib/`, `utils/`. A web-owned test living under `src/test/` instead is a bug. `src/test/` is for the three things that cannot be co-located: tests of the repo-root **`core/`** package (`src/test/core/…`, mirroring the `core/` layout — it lives outside `clients/web/` and has no harness of its own); the **`integration`** project (`src/test/integration/…` — _placement is the manifest_, picked up by a folder glob, with no enumeration to keep in sync); and **shared test infrastructure** (`renderWithMantine.tsx`, `setup.ts`, `fixtures/`).
   - **`clients/cli`, `clients/tui`, `clients/launcher`**: **all** tests in a top-level **`__tests__/`**, not beside their source. Their `tsconfig.json` excludes `**/*.test.*`, so a co-located test lands in **no** tsconfig project and fails `npm run verify:typecheck-coverage`.
   - **Root tooling**: a `scripts/*.mjs` helper with pure logic gets a sibling `*.test.mjs`. Keep that exact filename — `node --test` silently _skips_ a file its glob misses and still exits 0.
+- **Render Ink components through the TUI's own `render`** (`clients/tui/__tests__/helpers/renderTui.tsx`), never `ink-testing-library`'s directly. It is the same function with every frame ANSI-stripped, which is what keeps an assertion on styled text from depending on the ambient environment: Ink writes styling *inside* the styled run, so `<Text underline>I</Text>nfo` reaches the frame buffer with escapes between `I` and `nfo` and `toContain("Info")` fails. It only bites where chalk emits color — a developer whose shell exports `FORCE_COLOR` — so CI is green on a suite that is broken for them (#2207). A test that genuinely needs the raw bytes reads `stdout.lastFrame()` off the returned instance.
 - **Render React components through `renderWithMantine`** (`src/test/renderWithMantine.tsx`); do not hand-roll a bare `MantineProvider`, which skips the project theme and the helper's options and drifts from every other test. Pass the `colorScheme` option to exercise a forced scheme rather than hand-rolling `defaultColorScheme`. Use `renderWithMantineTransitions` **only** when a test must assert mid-flight transition state, and read the long comment on the helper before changing anything about it.
 - **The web coverage `include` is a whitelist.** It names `components`/`hooks`/`theme`/`lib`/`utils`/`server` plus the browser-consumed `core/*` runtime, so a module placed **outside** those directories falls out of the gate entirely, silently. Place new modules inside a gated directory. The documented exceptions — `src/App.tsx` and the `src/main.tsx` / `src/index.ts` bootstraps — are called out in a comment on the `include` array itself.