Update docx, xlsx, pdf, pptx skills with latest improvements

docx: Add commenting and track-changes support. Reorganize OOXML
tooling into a shared office/ module.

pptx: Streamline SKILL.md, add slide-editing and pptxgenjs guides,
bundle html2pptx as a tgz. Reorganize OOXML tooling into a shared
office/ module.

xlsx: Move recalc script into scripts/ and expand it. Add shared
office/ module for OOXML pack/unpack/validate.

pdf: Improve form-filling workflow with new form-structure extraction
script and updated field-info extraction.

skills/pdf/scripts/extract_form_field_info.py

@@ -4,11 +4,8 @@ import sys
 from pypdf import PdfReader
 
 
-# Extracts data for the fillable form fields in a PDF and outputs JSON that
-# Claude uses to fill the fields. See forms.md.
 
 
-# This matches the format used by PdfReader `get_fields` and `update_page_form_field_values` methods.
 def get_full_annotation_field_id(annotation):
     components = []
     while annotation:
@@ -25,12 +22,9 @@ def make_field_dict(field, field_id):
     if ft == "/Tx":
         field_dict["type"] = "text"
     elif ft == "/Btn":
-        field_dict["type"] = "checkbox"  # radio groups handled separately
+        field_dict["type"] = "checkbox"  
         states = field.get("/_States_", [])
         if len(states) == 2:
-            # "/Off" seems to always be the unchecked value, as suggested by
-            # https://opensource.adobe.com/dc-acrobat-sdk-docs/standards/pdfstandards/pdf/PDF32000_2008.pdf#page=448
-            # It can be either first or second in the "/_States_" list.
             if "/Off" in states:
                 field_dict["checked_value"] = states[0] if states[0] != "/Off" else states[1]
                 field_dict["unchecked_value"] = "/Off"
@@ -50,15 +44,6 @@ def make_field_dict(field, field_id):
     return field_dict
 
 
-# Returns a list of fillable PDF fields:
-# [
-#   {
-#     "field_id": "name",
-#     "page": 1,
-#     "type": ("text", "checkbox", "radio_group", or "choice")
-#     // Per-type additional fields described in forms.md
-#   },
-# ]
 def get_field_info(reader: PdfReader):
     fields = reader.get_fields()
 
@@ -66,19 +51,13 @@ def get_field_info(reader: PdfReader):
     possible_radio_names = set()
 
     for field_id, field in fields.items():
-        # Skip if this is a container field with children, except that it might be
-        # a parent group for radio button options.
         if field.get("/Kids"):
             if field.get("/FT") == "/Btn":
                 possible_radio_names.add(field_id)
             continue
         field_info_by_id[field_id] = make_field_dict(field, field_id)
 
-    # Bounding rects are stored in annotations in page objects.
 
-    # Radio button options have a separate annotation for each choice;
-    # all choices have the same field name.
-    # See https://westhealth.github.io/exploring-fillable-forms-with-pdfrw.html
     radio_fields_by_id = {}
 
     for page_index, page in enumerate(reader.pages):
@@ -90,8 +69,6 @@ def get_field_info(reader: PdfReader):
                 field_info_by_id[field_id]["rect"] = ann.get('/Rect')
             elif field_id in possible_radio_names:
                 try:
-                    # ann['/AP']['/N'] should have two items. One of them is '/Off',
-                    # the other is the active value.
                     on_values = [v for v in ann["/AP"]["/N"] if v != "/Off"]
                 except KeyError:
                     continue
@@ -104,17 +81,11 @@ def get_field_info(reader: PdfReader):
                             "page": page_index + 1,
                             "radio_options": [],
                         }
-                    # Note: at least on macOS 15.7, Preview.app doesn't show selected
-                    # radio buttons correctly. (It does if you remove the leading slash
-                    # from the value, but that causes them not to appear correctly in
-                    # Chrome/Firefox/Acrobat/etc).
                     radio_fields_by_id[field_id]["radio_options"].append({
                         "value": on_values[0],
                         "rect": rect,
                     })
 
-    # Some PDFs have form field definitions without corresponding annotations,
-    # so we can't tell where they are. Ignore these fields for now.
     fields_with_location = []
     for field_info in field_info_by_id.values():
         if "page" in field_info:
@@ -122,7 +93,6 @@ def get_field_info(reader: PdfReader):
         else:
             print(f"Unable to determine location for field id: {field_info.get('field_id')}, ignoring")
 
-    # Sort by page number, then Y position (flipped in PDF coordinate system), then X.
     def sort_key(f):
         if "radio_options" in f:
             rect = f["radio_options"][0]["rect"] or [0, 0, 0, 0]