Add native audio/image efferent surfaces + projector proof-of-shape

audio-surface.el / image-surface.el: own-core additive-synthesis WAV and
raster-PNG renderers (integer-only DSP, since EL has no floats), rendered
from learned engram signatures via a pluggable surface-profile
abstraction (surface-profile.el). audio-demo.el / image-demo.el are
drivers. NOTE: demo files hardcode absolute paths to this worktree's own
directory — will need a path fixup before landing.

elp/projector/ is a Python package the author's own README marks as
"STAGING/PROOF-OF-SHAPE — not the deliverable", superseded by the native
.el surface-profile work above; kept as a validated architecture proof.
Generated output (elp/faculty/{out,sig}, elp/projector/out,
__pycache__) intentionally excluded.

elp/projector/projectors/docx.py

@@ -0,0 +1,113 @@
+"""docx.py — the .docx surface projector: an OWN minimal OOXML emitter.
+
+Own-the-core: a .docx is just a ZIP of a few XML parts (WordprocessingML). We
+emit it with the standard library only — ``zipfile`` + string XML — no
+python-docx, no external dependency. This proves a "richer structured format"
+surface without importing anyone else's toolkit.
+
+Parts emitted (the minimal valid set + a styles part for real headings):
+    [Content_Types].xml
+    _rels/.rels
+    word/_rels/document.xml.rels
+    word/styles.xml          (Title / Heading1 / Heading2 / Normal)
+    word/document.xml        (the content)
+
+Like the markdown projector it reads only the IR's realized sentences; it
+invents nothing. The surface differs, the faithful content does not.
+"""
+from __future__ import annotations
+
+import io
+import os
+import sys
+import zipfile
+from xml.sax.saxutils import escape
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+from document_ir import DocumentIR  # noqa: E402
+from projectors.base import register  # noqa: E402
+
+_CONTENT_TYPES = """<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types">
+  <Default Extension="rels" ContentType="application/vnd.openxmlformats-package.relationships+xml"/>
+  <Default Extension="xml" ContentType="application/xml"/>
+  <Override PartName="/word/document.xml" ContentType="application/vnd.openxmlformats-officedocument.wordprocessingml.document.main+xml"/>
+  <Override PartName="/word/styles.xml" ContentType="application/vnd.openxmlformats-officedocument.wordprocessingml.styles+xml"/>
+</Types>"""
+
+_RELS = """<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
+  <Relationship Id="rId1" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument" Target="word/document.xml"/>
+</Relationships>"""
+
+_DOC_RELS = """<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
+  <Relationship Id="rId1" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/styles" Target="styles.xml"/>
+</Relationships>"""
+
+_W = "http://schemas.openxmlformats.org/wordprocessingml/2006/main"
+
+_STYLES = f"""<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<w:styles xmlns:w="{_W}">
+  <w:style w:type="paragraph" w:default="1" w:styleId="Normal"><w:name w:val="Normal"/>
+    <w:rPr><w:sz w:val="22"/></w:rPr></w:style>
+  <w:style w:type="paragraph" w:styleId="Title"><w:name w:val="Title"/>
+    <w:pPr><w:spacing w:after="240"/></w:pPr>
+    <w:rPr><w:b/><w:sz w:val="52"/></w:rPr></w:style>
+  <w:style w:type="paragraph" w:styleId="Subtitle"><w:name w:val="Subtitle"/>
+    <w:rPr><w:i/><w:sz w:val="28"/><w:color w:val="555555"/></w:rPr></w:style>
+  <w:style w:type="paragraph" w:styleId="Heading1"><w:name w:val="heading 1"/>
+    <w:pPr><w:spacing w:before="240" w:after="120"/><w:outlineLvl w:val="0"/></w:pPr>
+    <w:rPr><w:b/><w:sz w:val="34"/></w:rPr></w:style>
+  <w:style w:type="paragraph" w:styleId="Heading2"><w:name w:val="heading 2"/>
+    <w:pPr><w:spacing w:before="200" w:after="100"/><w:outlineLvl w:val="1"/></w:pPr>
+    <w:rPr><w:b/><w:sz w:val="28"/></w:rPr></w:style>
+</w:styles>"""
+
+
+def _para(text: str, style: str | None = None) -> str:
+    ppr = f"<w:pPr><w:pStyle w:val=\"{style}\"/></w:pPr>" if style else ""
+    return (f"<w:p>{ppr}<w:r><w:t xml:space=\"preserve\">"
+            f"{escape(text)}</w:t></w:r></w:p>")
+
+
+class DocxProjector:
+    surface = "docx"
+    media_type = ("application/vnd.openxmlformats-officedocument."
+                  "wordprocessingml.document")
+    ext = "docx"
+    modality = "text"
+
+    def _document_xml(self, doc: DocumentIR) -> str:
+        body: list[str] = [_para(doc.title, "Title")]
+        if doc.subtitle:
+            body.append(_para(doc.subtitle, "Subtitle"))
+        abstract = doc.meta.get("abstract")
+        if abstract is not None and abstract.sentences:
+            body.append(_para(abstract.text()))
+        for sec in doc.sections:
+            style = "Heading1" if sec.level <= 1 else "Heading2"
+            body.append(_para(sec.heading, style))
+            for block in sec.blocks:
+                t = block.text()
+                if t:
+                    body.append(_para(t))
+        return (f"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>"
+                f"<w:document xmlns:w=\"{_W}\"><w:body>"
+                + "".join(body)
+                + "<w:sectPr><w:pgSz w:w=\"12240\" w:h=\"15840\"/>"
+                  "<w:pgMar w:top=\"1440\" w:right=\"1440\" w:bottom=\"1440\" "
+                  "w:left=\"1440\"/></w:sectPr></w:body></w:document>")
+
+    def project(self, doc: DocumentIR) -> bytes:
+        buf = io.BytesIO()
+        with zipfile.ZipFile(buf, "w", zipfile.ZIP_DEFLATED) as z:
+            z.writestr("[Content_Types].xml", _CONTENT_TYPES)
+            z.writestr("_rels/.rels", _RELS)
+            z.writestr("word/_rels/document.xml.rels", _DOC_RELS)
+            z.writestr("word/styles.xml", _STYLES)
+            z.writestr("word/document.xml", self._document_xml(doc))
+        return buf.getvalue()
+
+
+register(DocxProjector())