Phase 3 — InnerTube + itag
Port the YT client matrix + request envelope + itag lookup table.
src/youtube/
* constants.rs — ClientsConstants.java verbatim. All six live
clients (WEB, WEB_EMBEDDED_PLAYER,
WEB_MUSIC_ANALYTICS, ANDROID, IOS, plus the
WEB_REMIX values for completeness). Base URLs
+ prettyPrint=false suffix.
* client_request.rs — ClientInfo / DeviceInfo / InnertubeClientRequestInfo
+ the 5 factory constructors NPE exposes
(ofWebClient, ofWebEmbeddedPlayer, ofCharts,
ofAndroid, ofIos). build_envelope() emits the
InnerTube JSON in NPE's exact insertion order;
build_desktop_envelope() is the WEB-fast-path
used by search/browse/next/resolve_url/comments.
* itag.rs — 57-entry itag table (14 progressive + 10 audio +
33 video-only). MediaFormat enum + ItagType
enum + ItagItem struct + lookup().
* parsing.rs — consent toggle + cookie generator (SOCS=CAE= /
SOCS=CAISAiAD), WEB client-version cache + sw.js
scrape, WEB/mobile header builders (mobile
deliberately strips X-YouTube-Client-Name +
Origin/Referer + Cookie per audit Track A §6.2),
android/ios UA templates, visitor_data bootstrap
POST to /youtubei/v1/visitor_id.
PARITY notes flagged in code:
* androidSdkVersion=36 + osVersion=16 but Android-15 in UA — NPE-intentional
* mobile clients send NO X-YouTube-Client-* headers
* audit doc says "53 entries" but tallies + NPE source = 57 ItagItems
Tests: 62 lib unit pass (up from 43 in Phase 2). All Phase 1 + Phase 2
smoke still green. Live InnerTube POSTs (visitor_data bootstrap +
/player) deferred to Phase 4 integration.
Kayos
3014410cba