feat(runtime): implement single-article consolidation runtime and modularize codebase

src/runtime/hygiene/assembler.py

@@ -0,0 +1,44 @@
+"""Grounded intermediate Markdown assembler."""
+
+from __future__ import annotations
+
+from typing import List, Optional
+
+from src.runtime.candidate.models import CandidateObject
+
+
+def assemble_intermediate_markdown(
+    title: str,
+    subtitle: Optional[str],
+    ordered_blocks: List[CandidateObject],
+) -> str:
+    """Assembles sanitized intermediate Markdown from validated editorial components."""
+    parts: List[str] = []
+
+    # Title as H1
+    clean_title = title.strip()
+    parts.append(f"# {clean_title}")
+
+    # Subtitle if present
+    if subtitle and subtitle.strip():
+        parts.append(f"*{subtitle.strip()}*")
+
+    # Ordered body blocks
+    for blk in ordered_blocks:
+        b_text = blk.text.strip()
+        if not b_text:
+            continue
+
+        if blk.type == "heading":
+            level = blk.level or 2
+            prefix = "#" * max(2, min(6, level))
+            parts.append(f"{prefix} {b_text}")
+        elif blk.type == "list_item":
+            parts.append(f"- {b_text}")
+        elif blk.type == "quote":
+            parts.append(f"> {b_text}")
+        else:
+            # Standard paragraph
+            parts.append(b_text)
+
+    return "\n\n".join(parts)