[Feature] Set up design-only PowerPoint presentation styles

[chrismaddalena]

Feature Description

Turn an uploaded PPTX into a draft Presentation style: a design-only source of masters, layouts, theme, and reusable assets. Ghostwriter analyzes the file, warns about authored slides, and guides a manager through confirming plain-language slide-type mappings rather than exposing raw PowerPoint internals.

Are you intending to implement this feature?

Yes.

Current Behavior

Ghostwriter treats a PPTX as an opaque input and relies on hard-coded layout positions and placeholder positions. Existing source slides stay in generated output. Managers cannot understand whether a new deck is suitable without opening PowerPoint and knowing master-slide internals.

Desired Behavior

A manager can upload a PPTX, see its presentation capabilities, and configure a draft presentation style. Ghostwriter suggests one primary layout for each supported slide type from names and placeholder capabilities, while the manager confirms ambiguous matches. Authored slides are identified and explained: they will not be used by recipe generation.

Use Case

Managers can prepare light, dark, or client-branded presentation styles without needing to name PowerPoint layouts perfectly or edit YAML.

Implementation Suggestions

Use “Presentation style” and plain-language slide types in the normal UI. Keep masters, layout names, placeholders, and raw identifiers in advanced details. The setup must not promise browser rendering or generated thumbnails; managers verify later output by downloading a fictional sample deck. Existing content-bearing PPTX templates remain Legacy and keep their existing generator path.

Stack this PR on the PR for #965.

Additional Information

Acceptance criteria

• PPTX analysis records slide dimensions, masters, layouts, placeholder capabilities, reusable assets, and authored-slide count.
• A content-bearing PPTX is not rejected solely for having slides, but the draft clearly explains that recipe generation ignores authored slides.
• The normal setup experience uses presentation-style and slide-type language; raw layout and placeholder details are advanced-only.
• Ghostwriter suggests mappings from layout names and placeholder types, but requires the manager to confirm mappings before they are used.
• Each MVP slide type has one primary mapped layout and named abstract slots such as title, body, image, footer, and notes where applicable.
• Missing or ambiguous mappings explain the needed slide type and content area in plain language and direct the manager to update the PowerPoint master/layout deck and re-upload.
• Presentation styles remain drafts until a compatible deck type is available; they are excluded from report generation while incomplete.
• Legacy PPTX templates are visibly distinguished from new presentation styles without breaking existing generation.
• Automated tests cover empty and content-bearing files, multiple masters, duplicate layout names, placeholder types, mapping suggestions, ambiguity, and legacy behavior.
• The PR includes setup screenshots and release notes.

Blocked by

• [Feature] Add draft template analysis and publication workflow #965