feat: --footer/--header with {page}/{pages} placeholders, center-aligned

md2pdf.py:
- Expose --footer and --header (was dead code before)
- Remove --forms flag (B2 fix — weasyprint 68.1 silently drops <input>)
- Substitution support: {page} → counter(page), {pages} → counter(pages)
- Center-aligned via @bottom-center / @top-center

md2doc.py:
- Add --footer and --header support via Word field codes (PAGE, NUMPAGES)
- Center-aligned paragraph in footer/header
- Same {page}/{pages} substitution API as md2pdf

Both tools:
- GFM task list support: - [ ] → ☐, - [x]/- [X] → ☑ (synced _bulletize)
- Help text explains placeholder syntax with examples

md2doc.py

@@ -63,9 +63,15 @@ COMMON = {
 
 
 def _bulletize(text: str) -> str:
-    """Turn markdown "- " list markers into bullets, skipping code/HTML blocks.
+    """Turn markdown list markers into bullets, skipping code/HTML blocks.
 
-    Copied verbatim from md2pdf.py per spec §3.3.
+    Supports GFM task lists:
+        - [ ]  → ☐  (empty checkbox, U+2610)
+        - [x]  → ☑  (checked checkbox, U+2611)
+        - [X]  → ☑
+        -      → •  (regular bullet)
+
+    Copied from md2pdf.py (kept in sync).
     """
     import re
     out, in_fence, in_html = [], False, False
@@ -78,8 +84,16 @@ def _bulletize(text: str) -> str:
                 in_html = True
             elif re.match(r"^</(table|div|section|figure)>", stripped, re.I):
                 in_html = False
-        if not in_fence and not in_html and line.startswith("- "):
-            line = "• " + line[2:]
+        if not in_fence and not in_html:
+            # GFM task list — checked
+            if line.startswith("- [x] ") or line.startswith("- [X] "):
+                line = "☑ " + line[6:]
+            # GFM task list — unchecked
+            elif line.startswith("- [ ] "):
+                line = "☐ " + line[6:]
+            # Regular bullet
+            elif line.startswith("- "):
+                line = "• " + line[2:]
         out.append(line)
     return "\n".join(out)
 
@@ -430,12 +444,160 @@ def _render_hr(doc, node, style: dict):
     add_paragraph_bottom_border(p, color="d8d8d8", size="6")
 
 
-def convert_md_to_doc(md_file: Path, output_file: Path, style: str = "elegant") -> Path:
-    """Convert a single markdown file to DOCX.
+def _set_section_text(section, location: str, text: str, template: str):
+    """Apply footer/header text to a docx Section.
 
-    Currently a stub — actual conversion logic in Task 4+.
+    location: 'footer' or 'header'.
+    text: literal text (may be empty — clears the field).
+    template: original template with {page}/{pages} placeholders (used to detect
+              whether to inject field codes).
+
+    For docx, page numbering uses Word field codes:
+        {page}  → PAGE field
+        {pages} → NUMPAGES field
+
+    Other text is literal.
     """
-    raise NotImplementedError("md2doc conversion not yet implemented")
+    import re
+    if location == 'footer':
+        target = section.footer
+    else:
+        target = section.header
+
+    # Clear default empty paragraph content (python-docx auto-creates one)
+    if not target.paragraphs:
+        target.add_paragraph()
+    p = target.paragraphs[0]
+    # Center-align the footer/header paragraph
+    from docx.enum.text import WD_ALIGN_PARAGRAPH
+    p.alignment = WD_ALIGN_PARAGRAPH.CENTER
+    # Clear existing runs
+    for run in list(p.runs):
+        run.text = ""
+
+    # Split template on placeholders
+    parts = re.split(r'(\{page\}|\{pages\})', template)
+    for part in parts:
+        if part == '{page}':
+            # Insert PAGE field code
+            _add_field_code(p, 'PAGE')
+        elif part == '{pages}':
+            _add_field_code(p, 'NUMPAGES')
+        elif part:
+            p.add_run(part)
+
+
+def _add_field_code(paragraph, field: str):
+    """Insert a Word field code (PAGE, NUMPAGES) into a paragraph via XML."""
+    run = paragraph.add_run()
+    # Build the field structure: <w:fldChar begin/> <w:instrText>PAGE</w:instrText> <w:fldChar end/>
+    fld_begin = OxmlElement('w:fldChar')
+    fld_begin.set(qn('w:fldCharType'), 'begin')
+    run._r.append(fld_begin)
+
+    instr_run = paragraph.add_run()
+    instr = OxmlElement('w:instrText')
+    instr.set(qn('xml:space'), 'preserve')
+    instr.text = f' {field} '
+    instr_run._r.append(instr)
+
+    sep_run = paragraph.add_run()
+    fld_sep = OxmlElement('w:fldChar')
+    fld_sep.set(qn('w:fldCharType'), 'separate')
+    sep_run._r.append(fld_sep)
+
+    # Placeholder for the rendered value (Word will compute on open)
+    placeholder_run = paragraph.add_run("?")
+    # Mark as dirty so Word recalculates
+    fld_dirty = OxmlElement('w:fldChar')
+    fld_dirty.set(qn('w:fldCharType'), 'end')
+    placeholder_run._r.append(fld_dirty)
+
+    # Set small font for footer/header runs
+    for r in [run, instr_run, sep_run, placeholder_run]:
+        r.font.size = Pt(7.5)
+        r.font.color.rgb = RGBColor.from_string("999999")
+
+
+def convert_md_to_doc(md_file: Path, output_file: Path, style: str = "elegant",
+                      footer: str = "", header: str = "") -> Path:
+    """Convert a single markdown file to DOCX."""
+    import re
+
+    style_cfg = STYLES.get(style, STYLES["elegant"])
+
+    with open(md_file, 'r', encoding='utf-8') as f:
+        md_content = f.read()
+
+    # Reuse _bulletize and BLANK_MARKER logic from md2pdf (copied, not imported)
+    md_content = _bulletize(md_content)
+
+    BLANK_MARKER = '<!--blank-line-->'
+    md_content = re.sub(
+        r'\n{3,}',
+        lambda m: '\n\n' + (BLANK_MARKER + '\n\n') * (len(m.group(0)) - 2),
+        md_content
+    )
+
+    html_content = markdown.markdown(
+        md_content,
+        extensions=[
+            'markdown.extensions.tables',
+            'markdown.extensions.fenced_code',
+            'markdown.extensions.toc',
+            'markdown.extensions.attr_list',
+            'markdown.extensions.md_in_html',
+            'markdown.extensions.nl2br',
+        ]
+    )
+    html_content = html_content.replace(
+        BLANK_MARKER, '<div style="height: 0.8em;"></div>'
+    )
+
+    soup = BeautifulSoup(html_content, "lxml")
+    doc = Document()
+
+    # Walk top-level elements in <body>
+    body = soup.find("body") or soup
+    for element in body.children:
+        if not hasattr(element, "name") or element.name is None:
+            continue
+        name = element.name
+
+        if name in ("h1", "h2", "h3", "h4"):
+            _render_heading(doc, element, level=int(name[1]), style=style_cfg)
+        elif name == "p":
+            _render_paragraph(doc, element, style=style_cfg)
+        elif name in ("ul", "ol"):
+            _render_list(doc, element, style=style_cfg)
+        elif name == "table":
+            _render_table(doc, element, style=style_cfg)
+        elif name == "pre":
+            _render_pre(doc, element, style=style_cfg)
+        elif name == "blockquote":
+            _render_blockquote(doc, element, style=style_cfg)
+        elif name == "hr":
+            _render_hr(doc, element, style=style_cfg)
+        elif name == "img":
+            _warn_skip_image(element)
+        elif name == "figure":
+            img = element.find("img")
+            if img:
+                _warn_skip_image(img)
+            else:
+                _render_paragraph(doc, element, style=style_cfg)
+        # else: silently skip unknown elements (divs, spans, etc.)
+
+    # Apply footer/header to all sections (typically just one)
+    if footer or header:
+        for section in doc.sections:
+            if footer:
+                _set_section_text(section, 'footer', footer, footer)
+            if header:
+                _set_section_text(section, 'header', header, header)
+
+    doc.save(output_file)
+    return output_file
 
 
 def main():
@@ -447,8 +609,17 @@ Examples:
   %(prog)s document.md                    Convert single file (elegant style)
   %(prog)s document.md -o report.docx     Convert with custom output name
   %(prog)s docs/                          Convert all .md files in directory
-  %(prog)s doc.md --style mono            Use monospace font
-  %(prog)s doc.md --style dark            Use dark theme
+  %(prog)s doc.md --style mono                  Use monospace font
+  %(prog)s doc.md --style dark                  Use dark theme
+  %(prog)s contract.md --footer "Confidential"  Add footer (static text)
+  %(prog)s doc.md --header "Project X"          Add header (static text)
+  %(prog)s doc.md --footer "Page {page}"        Add footer with page counter
+  %(prog)s doc.md --footer "Page {page} of {pages}"  Page counter with total
+
+Footer/Header placeholders (only when --footer/--header is used):
+  {page}   current page number (e.g. "3")
+  {pages}  total page count (e.g. "12")
+  Literal text is rendered as-is. Mix freely: "Page {page} of {pages} — Confidential"
 
 Available styles: elegant (default), default, dark, mono, report
         """
@@ -459,6 +630,14 @@ Available styles: elegant (default), default, dark, mono, report
     parser.add_argument('--style', choices=list(STYLES.keys()), default='elegant',
                         help='Style template (default: elegant)')
     parser.add_argument('-q', '--quiet', action='store_true', help='Suppress output')
+    parser.add_argument('--footer',
+                        help='Custom footer text (center-aligned). '
+                             'Supports {page} and {pages} placeholders: '
+                             '"Page {page} of {pages}"')
+    parser.add_argument('--header',
+                        help='Custom header text (center-aligned). '
+                             'Supports {page} and {pages} placeholders: '
+                             '"Section X — page {page}"')
 
     args = parser.parse_args()
 
@@ -508,7 +687,9 @@ Available styles: elegant (default), default, dark, mono, report
                 print(f"Converting: {md_file.name} -> {docx_file.name}...", end=' ', flush=True)
 
             docx_file.parent.mkdir(parents=True, exist_ok=True)
-            convert_md_to_doc(md_file, docx_file, args.style)
+            convert_md_to_doc(md_file, docx_file, args.style,
+                              footer=args.footer or "",
+                              header=args.header or "")
 
             if not args.quiet:
                 size_kb = docx_file.stat().st_size / 1024