feat(CDPBrowser): role locators + full skip-sweep implementation

Implements everything found implementable in a full audit of CDPBrowser's
remaining test skips against Obscura v0.2.0 and Chrome:

- Role locators ({role, text, exact}): in-page ARIA role resolver (explicit
  role attribute + implicit HTML-ARIA mapping) with accessible-name matching,
  a new 'role' find() strategy, and ARIA-checkbox support in check/uncheck.
- grabWebElements/grabWebElement: new CDPElementHandle + WebElement.js
  'cdpbrowser' case, addressed via a new _runSelected() that _run delegates
  to. Also fixes MultipleElementsFound.fetchDetails(), which previously threw
  against a sparse array of undefined elements.
- context parameter: composed with any active within() block via a scope-
  chain resolved layer by layer in find(), wired into every action that
  accepts one.
- Shadow DOM: single- and (where the engine allows) nested-level piercing.
- attachFile: real <input type=file> via the CDP DOM domain, or a synthetic
  dragenter/dragover/drop sequence with a duck-typed dataTransfer (no
  DataTransfer/DragEvent constructor dependency) for dropzone elements.
- #strict mode: pressKey() (new), and NonFocusedType via the shared
  focusCheck.js used by Playwright/Puppeteer/WebDriver.
- Network traffic recording: CDP Network.* events wired into the shared
  lib/helper/network contract.
- grabTextFrom(All) and contextual see/dontSee now use the visibleText()
  fallback on unreliable-innerText engines, matching waitForText.

Two bugs in the previous mandate's Obscura work were found and fixed along
the way: visibleText() appended a spurious trailing newline when the root
itself was a block-level element (not just its descendants), and the
dropzone path depended on DataTransfer/DragEvent, which Obscura doesn't
implement.

Narrowly re-guards what retesting proved still genuinely broken: nested
shadow DOM (Obscura never retroactively upgrades a custom element defined
after it's already parsed into another element's shadow root), native file
input uploads (DOM.setFileInputFiles sets the live state correctly but
Obscura's real multipart POST drops the file), a zero-size bounding rect for
a plain inline element, and the already-documented label-click-focus
non-determinism now also hit by two #strict mode tests. Two network-traffic
tests are skipped for pre-existing external-site content drift / navigation
timing unrelated to this work (reproduced identically against Puppeteer).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: DavertMik