feat: Office-Extraktion (docx/xlsx/pptx) fuer files-, mail- und notes-MCP

officeutil.py (analog pdfutil): server-seitige Text-Extraktion, damit das
LLM Inhalte als Text bekommt statt Base64-Blob. Verkabelt in files.read_file,
mail.read_attachment (und notes.read_resource, bereits in e34711d).
Aeltere Binaerformate (.doc/.xls/.ppt) und .rtf bewusst nicht behandelt --
is_office() False -> Fallback auf Rohdaten. requirements-extra: python-pptx.

War bereits deployed und lief (FileTypes-Tests 14 passed), lag aber
uncommittet im Arbeitsverzeichnis; ohne officeutil.py waere ein frischer
Clone seit e34711d kaputt gewesen.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XhHNJKk3RsHgUsJ27WQSom

officeutil.py

@@ -0,0 +1,103 @@
+"""Office-Dokumente (docx/xlsx/pptx) -> extrahierter Text fuer Files- und Mail-MCP.
+
+Analog zu pdfutil: server-seitige Extraktion, damit das LLM (OpenClaw wie claude.ai)
+den Inhalt als Text bekommt statt eines Base64-Blobs. Aeltere Binaerformate
+(.doc/.xls/.ppt) und .rtf koennen diese Libs nicht -> hier NICHT behandelt
+(is_office() liefert False, Aufrufer faellt auf Rohdaten zurueck).
+"""
+import base64
+import io
+
+from mcp.types import TextContent, EmbeddedResource, BlobResourceContents
+
+MAX_TEXT = 200000
+
+DOCX = "application/vnd.openxmlformats-officedocument.wordprocessingml.document"
+XLSX = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
+PPTX = "application/vnd.openxmlformats-officedocument.presentationml.presentation"
+
+_EXT = {".docx": DOCX, ".xlsx": XLSX, ".pptx": PPTX}
+
+
+def _docx_text(content):
+    import docx
+    d = docx.Document(io.BytesIO(content))
+    parts = []
+    for p in d.paragraphs:
+        if p.text.strip():
+            parts.append(p.text)
+    for ti, tbl in enumerate(d.tables, 1):
+        parts.append(f"[Tabelle {ti}]")
+        for row in tbl.rows:
+            parts.append(" | ".join(c.text.strip() for c in row.cells))
+    return "\n".join(parts)
+
+
+def _xlsx_text(content):
+    import openpyxl
+    wb = openpyxl.load_workbook(io.BytesIO(content), read_only=True, data_only=True)
+    parts = []
+    try:
+        for ws in wb.worksheets:
+            parts.append(f"--- Blatt: {ws.title} ---")
+            for row in ws.iter_rows(values_only=True):
+                if any(v is not None for v in row):
+                    parts.append("\t".join("" if v is None else str(v) for v in row))
+    finally:
+        wb.close()
+    return "\n".join(parts)
+
+
+def _pptx_text(content):
+    from pptx import Presentation
+    prs = Presentation(io.BytesIO(content))
+    parts = []
+    for i, slide in enumerate(prs.slides, 1):
+        parts.append(f"--- Folie {i} ---")
+        for shape in slide.shapes:
+            if shape.has_text_frame:
+                for para in shape.text_frame.paragraphs:
+                    t = "".join(run.text for run in para.runs)
+                    if t.strip():
+                        parts.append(t)
+            if getattr(shape, "has_table", False):
+                for row in shape.table.rows:
+                    parts.append(" | ".join(c.text for c in row.cells))
+    return "\n".join(parts)
+
+
+_HANDLERS = {
+    DOCX: ("Word-Dokument", _docx_text),
+    XLSX: ("Excel-Tabelle", _xlsx_text),
+    PPTX: ("PowerPoint", _pptx_text),
+}
+
+
+def _resolve(mime, label):
+    if mime in _HANDLERS:
+        return _HANDLERS[mime]
+    ext = "." + label.rsplit(".", 1)[-1].lower() if "." in label else ""
+    m = _EXT.get(ext)
+    return _HANDLERS.get(m) if m else None
+
+
+def is_office(mime, label=""):
+    """True fuer docx/xlsx/pptx (per MIME oder Endung)."""
+    return _resolve(mime, label) is not None
+
+
+def office_to_content(content, label, mime="", uri=None):
+    uri = uri or f"file://{label}"
+    kind, fn = _resolve(mime, label)
+    try:
+        text = fn(content)
+    except Exception as e:
+        return [
+            TextContent(type="text", text=f"[{kind} '{label}' konnte nicht gelesen werden ({e}). Rohdaten folgen.]"),
+            EmbeddedResource(type="resource", resource=BlobResourceContents(
+                uri=uri, blob=base64.b64encode(content).decode(),
+                mimeType=mime or "application/octet-stream")),
+        ]
+    if text.strip():
+        return [TextContent(type="text", text=f"[{kind}: {label}]\n\n{text[:MAX_TEXT]}")]
+    return [TextContent(type="text", text=f"[{kind} '{label}' enthaelt keinen extrahierbaren Text.]")]