Overrides document.cookie setter to intercept cookie writes and detect
unknown cookies not present in the banner config. Also scans pre-existing
cookies on startup. Detected cookies are debounced and reported in batches
to the detected-cookies endpoint with inferred durations from max-age/expires.
Extracts shared cookie helpers (parseCookieName, parseDuration, isDeletion,
removeCookies) into cookie-utils.ts, used by both activation.ts and
detector.ts. Unifies the duplicated "probo_consent" constant into a single
export from cookie.ts.
Signed-off-by: Émile Ré <emile@getprobo.com>