feat: enable HTML rich messages in Telegram poster

- Strip separator lines (━, —, -, =, etc.) automatically
- Format first line as bold HTML title (<b>Title</b>)
- Keep body text escaped and formatted
- Append hashtags at the end (#category #source)
- Pass parse_mode='HTML' in Telegram API requests

src/vk_parser_app/text_utils.py

@@ -31,12 +31,47 @@ def publication_hashtags(category_tag: str, source_tag: str) -> str:
     return " ".join(f"#{tag}" for tag in tags if tag)
 
 
-def build_publication_text(text: str, category_tag: str, source_tag: str) -> str:
+import html
+
+
+def build_publication_text(
+    text: str,
+    category_tag: str,
+    source_tag: str,
+    format_title: bool = False,
+    parse_mode: str | None = None,
+) -> str:
     base = strip_trailing_hashtag_line(text)
+    lines = base.splitlines()
+    sep_pattern = re.compile(r"^\s*[━—─\-=\*\#_]{2,}\s*$")
+    filtered_lines = [line for line in lines if not sep_pattern.match(line)]
+    if not filtered_lines:
+        return publication_hashtags(category_tag, source_tag)
+    title_idx = None
+    for idx, line in enumerate(filtered_lines):
+        if line.strip():
+            title_idx = idx
+            break
+    formatted_lines = []
+    for idx, line in enumerate(filtered_lines):
+        if idx == title_idx and format_title:
+            if parse_mode == "html":
+                escaped_title = html.escape(line.strip())
+                formatted_lines.append(f"<b>{escaped_title}</b>")
+            elif parse_mode == "markdown":
+                formatted_lines.append(f"**{line.strip()}**")
+            else:
+                formatted_lines.append(line.strip())
+        else:
+            if parse_mode == "html":
+                formatted_lines.append(html.escape(line))
+            else:
+                formatted_lines.append(line)
+    body = "\n".join(formatted_lines).strip()
     hashtags = publication_hashtags(category_tag, source_tag)
-    if not hashtags:
-        return base
-    return f"{base}\n\n{hashtags}" if base else hashtags
+    if hashtags:
+        return f"{body}\n\n{hashtags}" if body else hashtags
+    return body
 
 
 def parse_categories(value: object) -> list[str]: