feat: BRB backdrop seed + docs refresh + Polar org ID

- Add brb-backdrop.jpg asset, SeedBrbBackdrop() mirrors Starting pattern
- Update HANDOFF.md (was stale), TASKS.md (TASK 10 ready, TASK 15 2/5), ai.md (org ID)
- Polar org ID c05fb364 obtained via OAT, recorded in CREDENTIALS.md

HANDOFF.md

@@ -1,21 +1,25 @@
 # HANDOFF — Session State
 
 ## Branch
-`main` — dirty (social slot lock removal + doc updates)
+`main` — dirty (BRB backdrop + Polar org ID + doc updates, uncommitted)
 
 ## What shipped this session
-- **Branding palette + assets recorded** — `ai.md` Brand section (references `MARCOM.md`), `MARCOM.md` gets the full hex palette and asset inventory
-- **AI transparency statement** — `ai.md` Brand section documents AI-assisted pair-programming
-- **Monetization model updated** — `ai.md` Monetization section rewritten: no feature lock, only watermark difference; all features free for everyone
-- **TASKS.md updated** — TASK 10 re-scoped (Polar billing, watermark-only), tasks 15-18 added (stock bg images, infinity display fix, web source WebView2, local recording)
-- **TASK 10c shipped** — social slot locks removed: `SocialsDialogViewModel` no longer takes `isPremium` parameter, slots 3-6 always available, tests updated
-- **v1 feature completeness** — competitive gap analysis completed; 5 new tasks added (19-23) for table-stakes features: scene transitions, hotkeys, media source, audio sync offset, studio mode
-- **MONETIZATION.md updated** — v1 feature completeness section added with competitive context
-- **ai.md updated** — v1 task queue documented in Current limitations/TODOs section
+- **BRB backdrop seeded on every load** — `Assets/brb-backdrop.jpg` (user-provided image, Gemini-generated),
+  added as `<Resource>` in csproj; `SeedBrbBackdrop()` in MainViewModel mirrors the Starting pattern
+  (idempotent, skips if Background already exists). Runs on every startup outside the
+  `Scenes.Count == 0` guard.
+- **UI rename: Screens → Layers → Properties** — 16 UI text changes across MainWindow.xaml + MainViewModel.cs
+  (section headers, tooltips, context menus, empty hints, onboarding text, fallback display name).
+  Code identifiers unchanged.
+- **Polar org ID obtained** — `c05fb364-b967-4f6c-adf2-8a144e46d085` (Llama Chile Shop, slug: llamacasty).
+  Organization Access Token (OAT) stored in `Downloads/llamacasty-polar-code.txt`.
+  OATs are org-scoped — `organization_id` can be omitted from API calls.
+- **CREDENTIALS.md updated** — Polar org ID + validate endpoint + key prefix (`LCYT-`) recorded.
 
-## Polar.sh resources (from earlier session)
+## Polar.sh resources
 | Resource | ID |
 |---|---|
+| Org ID | `c05fb364-b967-4f6c-adf2-8a144e46d085` |
 | Product | `d105dfa1-497e-423b-8cd4-e0ee2e3abbc0` |
 | Price | `7c1b6f70-cf8c-46df-9bc8-6703f9fa64d0` |
 | Benefit | `80f66bc1-d5a3-44a1-b9ea-1709ae508535` |
@@ -23,6 +27,8 @@
 | LLAMAFOUNDER | `01a8c29f-9bb8-4e96-9cbe-417a6a5cec9b` |
 | LLAMA50 | `8cff803e-053f-49b4-8d12-d74d468f2943` |
 | Checkout URL | `https://buy.polar.sh/polar_cl_ueMy8AyAClO0o0yo19IroZwKTbD587gzUsjEW3bFapw` |
+| Customer-portal validate | `POST https://api.polar.sh/v1/customer-portal/license-keys/validate` |
+| Key prefix | `LCYT-` |
 
 ## Build
 ```bash
@@ -31,18 +37,25 @@ taskkill.exe /F /IM ytLive.exe  # if running
 "/mnt/c/Program Files/dotnet/dotnet.exe" vstest "C:\Users\gramp\Documents\Code\projects\ytLive\ytLive.Tests\bin\Debug\net8.0-windows10.0.19041.0\ytLive.Tests.dll"
 ```
 
+## Known issues
+- `Mix_HonorsProviderGains_AndGameMute_KillsTheLoopback` integration test is flaky — hangs when
+  run via `vstest` (likely tries to acquire WASAPI devices in headless CI). Exclude with
+  `--TestCaseFilter:"FullyQualifiedName!~Mix_HonorsProviderGains"` if needed.
+- Build often fails when ytLive.exe is running — `taskkill.exe /F /IM ytLive.exe` first.
+
 ## Next steps
-1. **Build + test** — verify social slot lock removal compiles and tests pass
-2. **TASK 9 item 4** — live chat (poll + render + badges) — already coded, just needs wiring
-3. **TASK 20** — hotkeys (global keyboard shortcuts) — small scope, huge UX impact
-4. **TASK 19** — scene transitions (Cut/Fade/Move/Custom) — already scoped
-5. **TASK 17** — web source WebView2 (enables alert ecosystem)
-6. **TASK 18** — local recording (independent)
-7. **TASK 21** — media source (video file playback) — pairs with TRAX for non-Live scenes
-8. **TASK 22** — audio sync offset — small, quality-of-life
-9. **TASK 23** — studio mode (lightweight preview)
-10. **TASK 15** — wait for user to provide stock scene background images
-11. **TASK 16** — kill infinity display (depends on TASK 15)
+1. **TASK 10 + Velopack** — license validation + auto-updates (1 full session). Polar org ID + OAT
+   now available; all infra ready. Phases: LicenseService, license key UI, brand flash gating,
+   Velopack integration, tests.
+2. **TASK 20** — hotkeys (global keyboard shortcuts) — small scope, huge UX impact
+3. **TASK 19** — scene transitions (Cut/Fade/Move/Custom) — already scoped
+4. **TASK 17** — web source WebView2 (enables alert ecosystem)
+5. **TASK 18** — local recording (independent)
+6. **TASK 21** — media source (video file playback) — pairs with TRAX for non-Live scenes
+7. **TASK 22** — audio sync offset — small, quality-of-life
+8. **TASK 23** — studio mode (lightweight preview)
+9. **TASK 15** — stock bg images — Starting and BRB seeded; Live, Chat, Ending still waiting on user images
+10. **TASK 16** — kill infinity display (depends on TASK 15 for Live/Chat/Ending images)
 
 ## v1 vision
 > A streaming tool that's intuitive and ready to go out-the-gate with nothing held back.
@@ -52,3 +65,4 @@ taskkill.exe /F /IM ytLive.exe  # if running
 - Polar checkout page ~80% configured — needs logo upload via dashboard
 - Logo upload API was broken (Polar server 500 on `/v1/files/{id}/uploaded`) — upload via dashboard instead
 - Full codebase rename (ytLlive → LlamaCasty) still pending
+- BRB backdrop image is user-provided (Gemini-generated) — may need replacement with branded image