feat(reporters): add accessible text status labels to the terminal reporter

[dchaudhari7177]

Closes #233. Part of #217 — this is the reporter half; the --accessible CLI flag that calls the setter belongs to that parent issue.

What

Screen readers either skip the Unicode status glyphs or announce them by character name ("check mark", "heavy multiplication x"), neither of which conveys status. Colour-blind users relying on glyph shape hit the same wall when colour is the only other signal.

• setAccessibleMode(v) / isAccessibleMode() exported from src/reporters/terminal.ts, default off.
• Every status glyph now goes through a single sym() lookup against a SYMBOLS / ACCESSIBLE_SYMBOLS pair, so there is one place to add a symbol and no way to miss a call site:

glyph	accessible
✓	[PASS]
✗	[FAIL]
⚠	[WARN]
–	[SKIP]
ℹ	[INFO]
→ (bullet)	>

• Colour is untouched — the same ANSI codes are emitted in both modes, asserted by a test.

Call sites covered: watchStatusIcon, renderWatchNoChanges, renderWatchChanges, renderWatchFirstRun (via the icon helper), renderNextActions, and the "What Was Not Tested" / security-diagnostic lines in renderRunTerminal. No raw glyph literals remain outside the symbol table.

One judgement call

The issue lists ❯ → >. There is no ❯ in the file; there is →, used in two distinct roles:

• leading bullet ( → Auto-enforce: …) — swapped to >, since that is the marker the issue means.
• status transition (tools: pass → fail) — left alone. It is prose inside a sentence, not a status symbol, and it reads correctly ("pass to fail"); pass -> fail would be worse. There's a test pinning both halves of this so the intent isn't lost.

Happy to swap the transition arrow too if you'd rather have it uniform.

Tests

tests/reporters-accessible.test.ts (new, 7 tests): default-off, glyphs preserved when off, every status glyph replaced when on, [SKIP] for skipped/unsupported, reversibility, ANSI codes identical across modes, and the bullet-vs-transition arrow distinction above.

All 7 fail with src/reporters/terminal.ts reverted to main, and pass with it.

Checks run locally

gate	before	after
vitest run	60 failed, 537 passed (63 files)	60 failed, 544 passed (64 files)
npm run typecheck	pass	pass
npm run lint	TypeError: Cannot read properties of undefined (reading 'Cjs')	same

The 60 failures and the lint crash are identical on pristine main on my machine — this PR adds 7 passing tests and changes nothing else.

Heads-up on the documented install

npm install as written in CONTRIBUTING fails here with ERESOLVE: the root pins typescript@7.0.2 (dev) while @typescript-eslint/eslint-plugin@8.64.0 → ts-api-utils@^2.5.0 resolves against it in a way npm rejects. npm ci fails the same way. I got a working tree with npm install --legacy-peer-deps, which is almost certainly why npm run lint then crashes inside @typescript-eslint/typescript-estree. Might be worth a separate issue — I didn't touch dependencies here.