Summary

Adds native Google Slides API support (presentations.batchUpdate) for building and editing slide decks programmatically:

Creating slides

• slides add-slide <presentationId> <image> — appends a slide with a full-bleed image and optional speaker notes (--notes or --notes-file for multiline markdown)
  • --before <slideId> — insert before a specific slide instead of appending to the end
• slides list-slides <presentationId> — lists all slides with their object IDs
• slides delete-slide <presentationId> <slideId> — removes a slide by object ID

Editing existing slides

• slides read-slide <presentationId> <slideId> — shows slide content: speaker notes, text elements, and image references (supports --json output)
• slides update-notes <presentationId> <slideId> --notes/--notes-file — updates speaker notes on an existing slide in-place without deleting/re-adding
• slides replace-slide <presentationId> <slideId> <image> — atomically swaps the image on a slide via the ReplaceImage API, optionally updating notes in the same batch (--notes or --notes-file)

Workflows

• Build a deck: gog slides create "My Deck", then add-slide for each image, delete-slide to remove the default blank slide.
• Edit existing slides: list-slides to get IDs, read-slide to identify content, replace-slide to swap images in-place, update-notes to fix speaker notes — no more error-prone delete+add-before dance.

Also registers ServiceSlides in the auth layer with presentations + drive scopes (including readonly support).

Changes

• internal/googleauth/service.go — register ServiceSlides in service order, info map, and scopesForServiceWithOptions
• internal/googleapi/slides.go — new Slides API client factory (follows sheets.go pattern)
• internal/cmd/slides.go — add six new subcommands to SlidesCmd
• internal/cmd/slides_add_slide.go — uploads image to Drive, creates slide + full-bleed image via batchUpdate, inserts speaker notes, cleans up temp Drive file. Supports --before <slideId> to control insertion position via InsertionIndex
• internal/cmd/slides_list_slides.go — fetches presentation and lists slide numbers + object IDs
• internal/cmd/slides_delete_slide.go — deletes a slide by object ID via batchUpdate
• internal/cmd/slides_read_slide.go — fetches presentation, finds target slide, extracts speaker notes text, text elements, and image references
• internal/cmd/slides_update_notes.go — clears existing notes and inserts new text via single batch (DeleteText + InsertText)
• internal/cmd/slides_replace_slide.go — uploads new image to Drive, uses ReplaceImage API to swap in-place, optionally updates notes in the same batch

Note

Requires the Google Slides API to be enabled on the GCP project backing the OAuth client.

Tests

• 22 tests total covering all six commands:
  • add-slide: no notes, with notes, notes-file precedence, JSON output, unsupported format, --before insertion, --before not found (7 tests)
  • delete-slide: success, empty ID validation (2 tests)
  • read-slide: full content, JSON output, slide not found, no notes (4 tests)
  • update-notes: inline notes, notes-file precedence, slide not found, empty notes validation (4 tests)
  • replace-slide: image only, with notes, JSON output, slide not found, no image on slide (5 tests)
• All existing tests passing (go test ./...)