feat: live engine sticker studio, VitePress guide, and v3.17.0 release

[spelech]

Summary

Implements live engine dispatch and alpha contour dilation for the Sticker Studio, provides a comprehensive VitePress documentation guide, modernizes the UI layout documentation in README.md, and bumps the release version to v3.17.0.

Key Changes

1. StickerContourProcessor (Alpha Dilation Engine):
   • High-performance, zero-dependency C# image processor.
   • Euclidean circular neighborhood contour dilation (^2 + dy^2 \le R^2$) applying solid die-cut white borders (0–24px).
   • BFS exterior boundary flood-fill for automatic subject cutout and transparent backgrounds.
   • Zero-dependency RFC 2083 PNG encoder/decoder.
2. Live Forge Diffusion Dispatch:
   • Wired \StickerGenerationService\ to local Stable Diffusion Forge (/sdapi/v1/txt2img\ and /sdapi/v1/img2img).
   • Integrated preset token synthesis (combining user prompt and 6 curated style presets).
   • Robust offline fallback with graceful failure handling without application crashes.
   • Post-processing pipeline passing diffusion outputs through \StickerContourProcessor.ApplyDieCutBorderToPng.
3. Documentation Suite:
   • Added \docs/studio/sticker-studio.md\ with detailed architecture, preset guide, and VRAM recommendations.
   • Updated \docs/.vitepress/config.mts\ sidebar navigation.
   • Modernized \README.md\ and \docs/USER_GUIDE.md\ to showcase the Dynamic Workspace (Activity Rail, Telemetry Ribbon, Dynamic Stage Container).
4. v3.17.0 Release Bump:
   • Synchronized version across all csproj files, native views, tray menus, health endpoints, web scripts, tests, and installer scripts.
   • Recompiled and updated browser-wasm distribution in \wwwroot/_framework/.

Verification

• Solution Tests: 793 passed, 0 failed, 6 skipped.
• Web Tooling:
  pm run lint,
  px tsc --noEmit, and
  pm run docs:build\ all passed with 0 errors.
• Code Review: Individual task reviews and Senior Code Review completed with Approval.