fix(kimi-ppt): block text overflow before rendering

[SuperstructureJH]

Summary

• replace the bundled Kimi PPT core with a build that evaluates text layout before rendering
• calculate overflow from glyph width, explicit line breaks, wrapping, font size, line height, letter spacing, bold weight, text direction, and text-box geometry
• fail pptd_render with actionable text-overflow errors and preserve the authored font size instead of silently shrinking text
• keep the existing 22-template Kimi-only catalog and adapter boundary unchanged

Verification

• source overflow and template-contract tests: 32/32 passed
• Kimi Host and Client bundle: passed
• Desktop Kimi/release tests: 34/34 passed
• Desktop complete suite: 701/701 passed across 84 files
• npm run typecheck: passed
• npm run build: passed
• git diff --check: passed

Acceptance boundary

• Implementation and automated package/build verification are complete.
• A fresh model-authored deck, rendered-slide visual review, and PowerPoint/WPS edit-save-reopen remain NOT_RUN.
• This PR is independent from fix(packaging): include Windows hidden console helper #305; template/version cleanup stays in that separate PR scope.