feat(slides): attach the slide design persona to the slides tool set

[Denis Fadeev (fadeev)]

Summary

Makes the slide design persona ride in with semantic tool selection the same way the App Builder prompt does. When the slides tool set activates (e.g. an implicit "make a deck about X"), its design guidance — layout catalog, palettes, font presets — is now appended to the conversation, not just the slide tools. Closes the asymmetry where app-generation attached APP_BUILDER_PROMPT but the slides set attached nothing.

The slide persona builder lived in slides/index.ts, which reaches @babel/parser via ./jsx, so the lib tool-set layer couldn't import it without bundling the heavy slide runtime. Rather than snapshot the prompt (drift risk, two sources of truth), this mirrors the existing appBuilderPrompt.ts extraction:

• FontPreset + FONT_PRESETS moved into the dependency-free fonts.ts.
• buildSlideSystemPrompt extracted into a new dependency-free slides/slidePrompt.ts, which exports SLIDE_BUILDER_PROMPT — the default-options instance, computed at load from the live design-system / palette / font catalogs (dynamic; no generated artifact, no drift).
• serverTools.ts imports SLIDE_BUILDER_PROMPT via the babel-free path and sets it as the slides tool set's systemPrompt — same field, same toolSetSystemPrompts collection, same additive role:system injection as app-generation.
• index.ts re-exports both for back-compat; its now-unused builder imports were trimmed.

The load-bearing guarantee holds structurally: slidePrompt.ts only reaches fonts / designSystem / palettes, all zero-import, so no @babel edge enters the lib bundle.

Built on the feat/app-gen-tool-improvements tool-set systemPrompt machinery (ToolSet.systemPrompt, toolSetSystemPrompts, computeToolGuidance, the toolGuidance injection) — which isn't on main yet. This PR therefore targets feat/app-gen-tool-improvements, not main; retarget/rebase onto main once that lands.

Gates: pnpm test (1280 passed), pnpm check (0 errors), pnpm build all green. The slides tool-set test was inverted to assert ["plan_deck"] now yields SLIDE_BUILDER_PROMPT.

Integration

None required. The implicit slide path picks up the persona automatically through the existing toolSetSystemPrompts machinery. SLIDE_BUILDER_PROMPT is newly exported from @anuma/sdk/tools if a host wants the default-options string directly. Optional later cleanup on the consumer: drop the detectSlideDeckIntent regex heuristic now that the semantic path carries the persona.

Breaking Changes

None. Additive systemPrompt field on the slides tool set plus a new SLIDE_BUILDER_PROMPT export; buildSlideSystemPrompt, FONT_PRESETS, FontPreset, and createSlideTools keep their exports and signatures.