fix(telegram): keep link targets literal during Markdown rendering

channel/telegram/telegram_markdown.py

@@ -104,14 +104,27 @@ def _render_line(line: str) -> str:
 
 
 def _render_inline(text: str) -> str:
+    links = {}
+    source = text
+
+    def emphasis(value: str) -> str:
+        value = _BOLD_RE.sub(r"<b>\1</b>", value)
+        value = _BOLD_ALT_RE.sub(r"<b>\1</b>", value)
+        value = _STRIKE_RE.sub(r"<s>\1</s>", value)
+        value = _ITALIC_RE.sub(r"<i>\1</i>", value)
+        return _ITALIC_ALT_RE.sub(r"<i>\1</i>", value)
+
     def link(m: re.Match) -> str:
         url = m.group(2).replace('"', "&quot;")
-        return f'<a href="{url}">{m.group(1)}</a>'
+        token = f"\x01link{len(links)}\x01"
+        while token in source:
+            token += "\x01"
+        links[token] = f'<a href="{url}">{emphasis(m.group(1))}</a>'
+        return token
 
-    text = _LINK_RE.sub(link, text)
-    text = _BOLD_RE.sub(r"<b>\1</b>", text)
-    text = _BOLD_ALT_RE.sub(r"<b>\1</b>", text)
-    text = _STRIKE_RE.sub(r"<s>\1</s>", text)
-    text = _ITALIC_RE.sub(r"<i>\1</i>", text)
-    text = _ITALIC_ALT_RE.sub(r"<i>\1</i>", text)
+    # URLs are not Markdown source. Park the anchor while surrounding prose
+    # is formatted, then restore it with the separately formatted label.
+    text = emphasis(_LINK_RE.sub(link, text))
+    for token, rendered in links.items():
+        text = text.replace(token, rendered)
     return text

docs/adr/ADR-027-telegram-literal-link-targets.md

@@ -0,0 +1,19 @@
+# ADR 027: fix(telegram): keep link targets literal during Markdown rendering
+
+Status: Accepted for this candidate.
+
+## Context
+
+The Telegram renderer creates anchor tags before running emphasis substitutions over the complete HTML. URL path segments such as __archive__ become bold tags inside href, corrupting the destination and Telegram parse mode.
+
+## Decision
+
+Park rendered links during the emphasis passes, apply formatting to labels, and restore links afterward. Use collision-safe placeholders so original text is not mistaken for a parked link.
+
+## Consequences
+
+Link destinations remain escaped literal URLs; label, surrounding emphasis, and inline code formatting continue to work.
+
+## Validation
+
+The focused regression fails on the unmodified base and passes with this change. tests/test_telegram_markdown_link_targets.py tests/test_telegram_markdown_fences.py passed locally; changed Python files passed CI-equivalent Ruff F checks. These are local native-contract checks using controlled doubles, not live provider or channel acceptance.

tests/test_telegram_markdown_link_targets.py

@@ -0,0 +1,35 @@
+"""Markdown link targets are literal URLs, not emphasis source."""
+import pytest
+
+from channel.telegram.telegram_markdown import to_telegram_html
+
+
+@pytest.mark.parametrize("url", [
+    "https://example.invalid/__archive__/report",
+    "https://example.invalid/a*b*c",
+    "https://example.invalid/~~draft~~",
+    "https://example.invalid/api?first=1&path=__value__",
+])
+def test_link_url_is_not_rewritten_as_inline_markup(url):
+    expected = url.replace("&", "&")
+    assert to_telegram_html(f"[report]({url})") == f'<a href="{expected}">report</a>'
+
+
+def test_link_label_and_surrounding_emphasis_keep_formatting():
+    assert to_telegram_html("**[Read *this*](https://example.invalid/__docs__)**") == (
+        '<b><a href="https://example.invalid/__docs__">Read <i>this</i></a></b>'
+    )
+
+
+def test_inline_code_in_link_label_still_restores():
+    assert to_telegram_html("[`__name__`](https://example.invalid/__docs__)") == (
+        '<a href="https://example.invalid/__docs__"><code>__name__</code></a>'
+    )
+
+
+def test_multiple_links_and_literal_placeholder_text_are_preserved():
+    source = "\x01link0\x01 [one](https://example.invalid/__a__) and [two](https://example.invalid/__b__)"
+    assert to_telegram_html(source) == (
+        '\x01link0\x01 <a href="https://example.invalid/__a__">one</a> and '
+        '<a href="https://example.invalid/__b__">two</a>'
+    )