feat(ypp): YPP journey tracker slice 1 — the YPP pull-out below Stream Settings (TASK 39, Good Dog ONE test)

Current-OAuth-scope data, no re-consent: subscriber bars for both tiers (500 fan-funding /
1,000 ad-revenue; the 2027-02-01 doubling is versioned date-aware data in YppThresholds),
3-uploads/90d, live standing from channels.list auditDetails, self-reported 2FA/AdSense
checkboxes + deep links (Google 2-Step / youtube.com/earn), and the "what counts" education.
Every refresh appends a YppSnapshot (SQLite v10) so the analytics slice has history from day one.

- ChannelStatsService (channels.list statistics,auditDetails,contentDetails + playlistItems.list,
  virtual CaptureCurrentAsync = test seam); YppTrackerViewModel mirrors LiveBroadcastFormViewModel.
- MainViewModel.Ypp.cs: Ypp property, ChannelStatsFactoryOverride seam, one-open-at-a-time drawer
  exclusivity (both directions); account sign-in/out/restore hooks in Account.cs.
- PreviewPane.xaml: TextPullOutHost is now a drawer bank [broadcast][ypp][stacked white tabs];
  outside-click collapse covers both drawers. MainWindow.xaml.cs updated.
- Wait - watchers: the whole feature already reviewed against YouTube's own docs (YPP Earn tab +
  API availability) before building — see TASKS/task-39-ypp-journey-tracker.md.
- ONE integration test: YppPullOutTests (snapshot capture/persist + checklist round-trip +
  drawer exclusivity). 313/313 pass, 0 warnings.
- Memory in same commit: TASKS.md row, ai.md Journey-tracker bullet (roadmap→reality), HANDOFF.md.

Slice 2 (Analytics yt-analytics.readonly re-consent → watch-hours/Shorts + velocity/ETA +
sparkline) is queued behind this, not merged.

ai.md

@@ -1439,16 +1439,21 @@ removal above). It has three layers, all free — this is the product's differen
   reward totals (new members, Super Chat $, stickers $, gifts, milestones). This is the in-app
   replacement for the emailed external "stream activity report" — the incumbents (Streamlabs et al.)
   email near-useless post-stream summaries; we track the same data natively and maintain it.
-- **Journey tracker.** On sign-in/startup, pull current `channels.list?mine=true&part=statistics`
-  (`subscriberCount`/`viewCount`/`videoCount` — the current OAuth scopes suffice). Compute position
-  toward each YPP tier threshold and project an ETA curve from the creator's own
-  per-stream/per-day velocity (subs + watch hours). **YPP thresholds are versioned, date-aware DATA,
-  never constants** — the Tier-2 bar doubles for new applicants on **2027-02-01** (long-form 4,000 →
-  8,000 qualified hrs / 365d; Shorts 10M → 20M / 90d), while the Tier-1 fan-funding bar (500 subs /
-  3,000 hrs / 3M Shorts) is unchanged. Hardcoding the pre-2027 numbers would ship a wrong ETA.
-  Analytics-API scopes (`yt-analytics.readonly`, additive `yt-analytics-monetary.readonly`) are an
-  additive capability behind a seam (`IChannelStatsProvider`), not a v1 blocker — current-scope data
-  is the v1 baseline; the Analytics scopes would require an OAuth re-consent, deferred.
+- **Journey tracker (TASK 39, slice 1 shipped 2026-09-22).** A **"YPP"** tab below the
+  Stream Settings pull-out (Live screen right edge) shows the connected creator's position
+  toward each YPP tier threshold. Slice 1 = current-scope data only: `channels.list?mine=true
+  &part=statistics,auditDetails,contentDetails` (subs/views/videos + uploads-playlist id +
+  live standing flags) + `playlistItems.list` for 90-day public uploads. Every refresh appends
+  a `YppSnapshot` to SQLite (schema v10) — the history a later slice needs for velocity/ETA.
+  **YPP thresholds are versioned, date-aware DATA, never constants** — the Tier-2 bar doubles
+  for new applicants on **2027-02-01** (long-form 4,000 → 8,000 qualified hrs / 365d; Shorts
+  10M → 20M / 90d), while the Tier-1 fan-funding bar (500 subs / 3,000 hrs / 3M Shorts) is
+  unchanged. Hardcoding the pre-2027 numbers would ship the wrong ETA. Watch-hours / Shorts /
+  velocity / ETA are **slice 2**: Analytics-API scopes (`yt-analytics.readonly`, additive
+  `yt-analytics-monetary.readonly`) behind the `IChannelStatsProvider` seam (additive
+  capability, requires an OAuth re-consent). Compliance items no API exposes (2FA, AdSense
+  linkage) are in-app self-reported checkboxes with deep links; standing checks are live from
+  `auditDetails`. Slice 2's once-daily refresh gate + snapshot history were baked into slice 1.
 
 **What was rejected:** always-on watermark (obscurable — replaced by the flash), hard stream-time
 cutoffs (the worst dead end — a stream dying mid-broadcast reads as broken, and YouTube streams