Add detector.ignoreSelectors: one component-level opt-out instead of an attribute per instance

An author who wants a rule off for one component has had two choices: put
`data-impeccable-ignore` on every instance, or silence the rule (or the
file) for the whole project. On impeccable-site #34 that meant eleven
attributes on eleven copies of the same 10px label for `undersized-ui-text`,
25 opt-out attributes in all. The count is the problem: the markup carries
noise, and the reviewer never sees how much was waived.

`detector.ignoreSelectors` is the declared twin of that attribute. One entry,
`{ rule, selector }`, waives the rule for every element the selector matches
and for that element's subtree, the same waiver the attribute grants the
element carrying it:

    impeccable ignores add-selector undersized-ui-text ".ks-tag" \
      --reason "10px mono index labels, confirmed"

The waiver is never silent. The engines stamp a waived finding with
`ignoredBy: "<selector>"` instead of dropping it; the config layer drops and
counts, and every scan prints one line per entry on stderr, in `--json` runs
too, so stdout stays the findings array:

    3 undersized-ui-text hits ignored by detector.ignoreSelectors on .ks-tag.

Where it applies: the browser engine (`BrowserConfig.ignoreSelectors`, also
readable from `window.__IMPECCABLE_CONFIG__`), the static HTML engine
(`DetectHtmlOptions.ignore_selectors`, and the `ignoreSelectors` option of
the wasm `detect_html_source_json` export), the detect CLI, and the design
hook. The text engine has no DOM and ignores the key. Entries can be scoped
with `files` globs like `ignoreValues`; `--no-config` disables them; `doctor`
validates their rule ids alongside `ignoreRules`. Nothing changes for a
project without the key: the engines stamp nothing, the CLI prints nothing,
the config writer does not add an empty `ignoreSelectors`, and the
per-instance attribute keeps working exactly as before.

Coverage: `crates/html/tests/selector_ignores.rs` (component, subtree,
wrong-rule, `*`, attribute parity), driver tests over the fake DOM,
`crates/detect` config tests (normalize, merge, per-target narrowing, the
tally), and oracle cases `detect-selector-ignore-*` / `ignores-selector-*`
over a new workspace. The eight re-recorded context/doctor goldens differ
only in the recognized-detector-keys sentence, which now lists the new key.

Assisted-by: Claude Code
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LQBUunp8QttxZqihybNmtL

docs/ENGINE.md

@@ -204,11 +204,19 @@ over the file-scanning engines, JSON in and JSON out:
 - `detect_text_json(content, file_path, options_json)`
 - `detect_html_source_json(html, file_path, options_json)`
 
-Both take `{ inlineIgnores?: boolean, designSystem?: { frontmatter?, sidecar? } }`
+Both take
+`{ inlineIgnores?: boolean, designSystem?: { frontmatter?, sidecar? }, ignoreSelectors?: [{ rule, selector }] }`
 and return the findings array `impeccable detect --json` prints, same keys and
 same order. `designSystem` carries the DESIGN.md inputs rather than a
 normalized object, because the JS API's normalized form used `Set`s and
-`Map`s that JSON cannot hold. Unparseable options fall back to the defaults.
+`Map`s that JSON cannot hold. `ignoreSelectors` is the project's
+component-level opt-out (`detector.ignoreSelectors`), already narrowed by the
+host to the entries whose `files` globs cover this file: a finding on an
+element the selector matches, or on a descendant of one, comes back carrying
+`ignoredBy: "<selector>"` rather than being dropped, so the host can count
+what an author's opt-out silenced and say so. Only the HTML engine matches
+selectors; the text engine has no DOM and ignores the key. Unparseable
+options fall back to the defaults.
 `antipatterns_json()` lists the built-ins followed by any pack's rows, and
 `immediate_tier_rules_json()` returns the design hook's immediate tier (the
 rule ids worth fixing at the edit site). That list lives in