fix: publish-to-pages — handle large presentations with external assets

[AndreaGriffiths11]

Fixes large PPTX/PDF handling per AndreaGriffiths11/publish-to-pages#1

Changes

• Auto-detects large files (>20MB or >50 images/pages) and saves assets externally instead of base64-inlining
• Pre-flight warning at 150MB suggesting PDF conversion path
• publish.sh now handles multi-file repos (HTML + assets/ directory)
• Backward compatible — small files still produce a single self-contained HTML
• Added --external-assets / --no-external-assets flags for manual control

[Copilot]

Pull request overview

This PR improves the publish-to-pages skill to better handle large PPTX/PDF inputs by switching to an external assets/ directory when output would otherwise become an extremely large single HTML file, and updates publishing to support multi-file output.

Changes:

• Add auto-detection (and manual flags) to emit images/pages into an assets/ directory for large PPTX/PDF conversions.
• Add large-file preflight warnings (150MB+) for PPTX/PDF conversions.
• Update publish.sh to publish index.html plus an adjacent assets/ directory when present.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
skills/publish-to-pages/scripts/publish.sh	Copies an adjacent assets/ folder into the repo and stages all files for publishing.
skills/publish-to-pages/scripts/convert-pptx.py	Adds external-assets mode, large-file detection/warnings, and CLI flags for PPTX conversion.
skills/publish-to-pages/scripts/convert-pdf.py	Adds external-assets mode, large-file detection/warnings, and CLI flags for PDF conversion.
skills/publish-to-pages/SKILL.md	Documents external-assets mode behavior, thresholds, and publishing requirements.

Comments suppressed due to low confidence (1)

skills/publish-to-pages/scripts/convert-pptx.py:374

• --external-assets and --no-external-assets can both be provided at the same time; currently the script will silently prefer --external-assets. Make these flags mutually exclusive (and produce a clear argparse error when both are set) so the CLI has deterministic, user-friendly behavior.

    parser = argparse.ArgumentParser(description="Convert PPTX to HTML presentation")
    parser.add_argument("input", help="Path to .pptx file")
    parser.add_argument("output", nargs="?", help="Output HTML path (default: same name with .html)")
    parser.add_argument("--external-assets", action="store_true", default=None,
                        help="Save images as separate files in assets/ directory (auto-detected for large files)")
    parser.add_argument("--no-external-assets", action="store_true",
                        help="Force inline base64 even for large files")
    args = parser.parse_args()

    ext_assets = None  # auto-detect
    if args.external_assets:
        ext_assets = True
    elif args.no_external_assets:
        ext_assets = False

[Copilot]

Because this script runs with set -euo pipefail, the find ... | wc -l pipeline inside the echo will cause the entire publish to abort if find returns non-zero (e.g., permission errors, unreadable files, broken symlinks). Consider making the file-counting best-effort (suppress errors / avoid failing the script) or dropping the count entirely so copying assets/ can’t fail due to the diagnostic output.

Suggested change

	echo "Copied assets/ directory ($(find "$HTML_DIR/assets" -type f | wc -l) files)"
	asset_count=$(find "$HTML_DIR/assets" -type f 2>/dev/null | wc -l || true)
	echo "Copied assets/ directory (${asset_count:-0} files)"

[Copilot]

io and re are imported but not used anywhere in this script. Removing unused imports will reduce noise and avoid confusing future maintainers about expected behavior.

This issue also appears on line 361 of the same file.

Suggested change

	import io
	import os
	import re
	import os

[Copilot]

--external-assets and --no-external-assets can both be provided at the same time; currently the script will silently prefer --external-assets. Make these flags mutually exclusive (and produce a clear argparse error when both are set) so users can’t accidentally get the opposite behavior than intended.