Introduce render gate and chart caching

Replace UI DispatcherTimer polling with a StudySnapshotRenderGate across multiple widgets to queue and apply only the latest analytics snapshot; components updated include StudyDeductionReasonsWidget, StudyEnvironmentWidget, StudyInterruptDensityWidget, StudyNoiseCurveWidget. Add StudySnapshotRenderGate implementation to coordinate rendering and monitoring leases and update subscription/lease lifecycle handling (subscribe/unsubscribe, Acquire/Dispose leases, Clear/Dispose gate). Rewrite chart controls (StudyNoiseCurveChartControl and StudyNoiseDistributionScatterChartControl) to use stable logical-time origins, split series into static vs dynamic tails, add geometry/sample caching, stable jitter/coordinate mapping helpers, and expose internal helpers & counts for testing. Add unit tests (StudyComponentRenderingTests) covering the render gate and chart behaviors (layer counts, logical X mapping, stable jitter, cache rebuild). These changes improve rendering correctness and performance by avoiding redundant renders and enabling deterministic chart layout.

.trae/specs/pdc-incremental-migration/spec.md

@@ -12,29 +12,33 @@ Replace VeloPack-based incremental packaging with a unified PDC FileMap + object
 
 ## Stage 2 (Current Implementation Target)
 
-- Move release publishing to PDCC + `phainon.yml` (ClassIsland-style).
-- Promote PDC-distributed FileMap/object-repo as the primary incremental path.
+- Use GitHub Actions PloNDS static publishing as the active incremental path.
+- Keep `phainon.yml` for future PDCC parity, but do not rely on PDCC for the current release flow.
+- Promote PloNDS-distributed FileMap/object-repo as the primary incremental path.
 - Keep GitHub Release installers and metadata as parallel distribution.
 - Keep Launcher state machine ownership (`.current/.partial/.destroy` + snapshots).
-- Update source defaults to `stcn` (S3/PDC), with GitHub fallback.
+- Check updates in order: NS3/PloNDS static source, GitHub Release PloNDS assets, then GitHub full installer.
 - S3 object root is fixed to `lanmountain/update/` with no update-system version prefix.
+- Public object URLs come from `S3_PUBLIC_BASE_URL`; do not infer them from `S3_ENDPOINT` and `S3_BUCKET`.
 
 Expected S3 layout:
-  - `lanmountain/update/repo/<hash-prefix>/<hash-object>`
-  - `lanmountain/update/meta/channels/<channel>/<subchannel>/latest.json`
-  - `lanmountain/update/meta/distributions/<distributionId>/*.json`
-  - `lanmountain/update/installers/<platform>/<arch>/*`
+  - `lanmountain/update/repo/sha256/<hash-prefix>/<hash-object>`
+  - `lanmountain/update/meta/channels/<channel>/<platform>/latest.json`
+  - `lanmountain/update/meta/distributions/<distributionId>.json`
+  - `lanmountain/update/manifests/<distributionId>/plonds-filemap.json`
+  - `lanmountain/update/manifests/<distributionId>/plonds-filemap.json.sig`
+  - `lanmountain/update/installers/<platform>/<version>/*`
 
 ## Acceptance
 
-- `release.yml` includes PDCC publish steps and no Velopack steps.
+- `release.yml` contains no Velopack steps; PloNDS static publishing is handled by `plonds-build.yml` and `ddss-publish.yml`.
 - Release jobs keep building installers for Windows x64/x86, Linux x64, and macOS.
-- PDC metadata + FileMap + object repo are published under `lanmountain/update/`.
-- Host can consume PDC payload (`stcn` source) and fallback to GitHub when unavailable.
+- PloNDS metadata + FileMap + object repo are published under `lanmountain/update/`.
+- Host can consume the NS3/PloNDS static payload and fallback to GitHub when unavailable.
 - Launcher can apply both:
   - legacy signed `files.json + update.zip`
-  - PDC FileMap object-repo payload.
-- Rollback semantics remain unchanged.
+  - PloNDS FileMap object-repo payload.
+- Rollback semantics keep both automatic failure rollback and manual rollback after a successful update.
 
 ## Deprecated Notes