…e cursor drift

The composer's `cursorLayout` (in `ui-tui/src/lib/inputMetrics.ts`) used a
hand-rolled word-wrap algorithm to decide where `useDeclaredCursor`
should park the hardware cursor. But Ink's `<Text wrap="wrap">` renders
the same text via `wrap-ansi`. The two algorithms disagreed on common
real-world inputs — `"branch investigate"` at cols=20, `"hello world"`
at cols=8, exact-fill strings like `"abcdefgh"` at cols=8 — so the
hardware cursor parked several cells past where Ink actually rendered
the last character. Users saw a multi-cell blank gap between their
last-typed letter and the cursor block, especially on narrow terminals
(the Cursor IDE built-in terminal was the worst offender).

Three previous PRs (#26717, #25860, #22197) chased fast-echo
displayCursor/cursorDeclaration drift and in-band-vs-native cursor
heuristics. None of them touched the underlying wrap-algorithm
mismatch, which is why the bug kept resurfacing.

Fix: source cursorLayout's line breaks from wrap-ansi directly. Walk
its emitted string char-by-char, tracking original-string offsets, push
a VisualLine at each '\n'. Also drop the buggy `column >= w` overflow
rule in cursorLayout — that's what pushed exact-fill text onto a
phantom next row.

canFastBackspaceShape now detects the wrap boundary in BOTH coordinate
conventions (column === 0 OR column >= columns), since exact-fill now
reports as (0, columns) instead of the previous (1, 0). The physical
state is identical — the terminal auto-wraps at column N either way —
but the layout function reports the position more honestly.

Tests:
- ui-tui/src/__tests__/textInputWrap.test.ts: 3 tests that pinned the
  BUGGY behavior were updated to assert wrap-ansi parity (the real
  invariant). Added a typing-prefix invariant: cursorLayout must agree
  with wrap-ansi at every character of a long input.
- ui-tui/src/__tests__/cursorDriftRegression.test.ts: new file. Walks
  the user-reported bug message char-by-char at 7 widths and asserts
  agreement with wrap-ansi at every prefix.

Verification:
- 791/791 vitest tests pass.
- 84/84 tui-gateway pytest tests pass via scripts/run_tests.sh.
- PTY repro (typing into a real `hermes --tui` PTY at cols=50/55/60):
  cursor lands exactly 1 cell past the last typed char in every case
  the bug previously drifted.

Three small follow-ups from the Copilot review on #27489:

1. Declare `wrap-ansi` as a direct dependency of `ui-tui`. It was a
   phantom dep that resolved via npm hoisting from `@hermes/ink`'s
   transitive graph — fine on hoisted installs, but breaks under pnpm
   or `npm install --no-install-strategy=hoisted` style isolated
   installs. Now listed as `"wrap-ansi": "^9.0.0"` matching the
   @hermes/ink version. Lockfile regenerated.

2. Implement the defensive resync the comment promised. Previously the
   comment claimed the loop would "fall back to advancing by one to
   stay in lockstep" on wrap-ansi desync, but the code unconditionally
   advanced `originalIdx` with no actual check — so any future
   wrap-ansi option change or styled-input caller could silently slide
   `originalIdx` past the end of `value` and emit garbage line ranges.
   Now actually compares `value[originalIdx] === ch`, re-syncs via
   `indexOf` on mismatch, and bails out (returning whatever was built
   so far) if the desync is unrecoverable. Production paths still hit
   the equality fast-path on every char.

3. Drop the `visualLines` wrapper. It was a one-line indirection over
   `visualLinesFromWrappedOutput`. Renamed the implementation to
   `visualLines` and removed the wrapper — same name, no extra layer.

No behavior change beyond the defensive realign; all 791 vitest tests
still pass.

…n runtime parity)

Copilot caught an important runtime parity gap on PR #27489: the fix
imported the npm `wrap-ansi` package directly, but Ink's `<Text
wrap="wrap">` uses a runtime-selecting shim
(`ui-tui/packages/hermes-ink/src/ink/wrapAnsi.ts`) that prefers
`Bun.wrapAnsi` when running under Bun and falls back to the npm package
elsewhere. So under Bun, Ink would render via `Bun.wrapAnsi` while
`cursorLayout` would compute breaks via the npm package — any
disagreement reintroduces the exact cursor-drift symptom the PR is
meant to eliminate.

Fix:

- Export `wrapAnsi` from `@hermes/ink` (`packages/hermes-ink/src/entry-exports.ts`
  and `packages/hermes-ink/index.d.ts`) so the shim is the public surface.
- Switch `ui-tui/src/lib/inputMetrics.ts` from `import wrapAnsi from
  'wrap-ansi'` to `import { wrapAnsi } from '@hermes/ink'`. Both
  renderer (Ink) and cursor layout now traverse the same shim, so
  they share the runtime-selected implementation by construction.
- Same swap in `textInputWrap.test.ts` and `cursorDriftRegression.test.ts`
  — tests now assert parity through the shim, which means under Bun
  they actually exercise Bun's implementation instead of asserting a
  tautology against the npm package.
- Drop the direct `"wrap-ansi": "^9.0.0"` from `ui-tui/package.json`.
  `@hermes/ink` (which IS a declared dep) pulls wrap-ansi in
  transitively — that's not a phantom dep because the import path
  goes through `@hermes/ink`'s public exports, not through a
  hoisting accident.

Verified: 791/791 vitest tests pass. `@hermes/ink` rebuilt
(`dist/entry-exports.js` includes `wrapAnsi` export). TUI bundle
rebuilt clean.

… minimal