feat(notion-writer): add GitHub-alert callout blocks

Adds support for > [!NOTE] / > [!TIP] / > [!IMPORTANT] / > [!WARNING] /
> [!CAUTION] callouts. Each alert type maps to a Notion callout block
with an emoji icon and matching colored background. Unknown alert types
(e.g. > [!BOGUS]) fall through to the existing quote handler with the
marker preserved.

Also restores the "must come before generic bullet match" comment on
the todo branch (load-bearing ordering note).

+6 tests, 22 passing total.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

custom-skills/32-notion-writer/code/scripts/test_parser.py

@@ -165,6 +165,52 @@ def test_blocks_table():
             "link inline formatting preserved inside table cell")
 
 
+def test_callout_note():
+    md = "> [!NOTE]\n> This is a note.\n> Spans multiple lines."
+    blocks = markdown_to_notion_blocks(md)
+    _assert(len(blocks) == 1, "exactly one block emitted")
+    _assert(blocks[0]["type"] == "callout", "block type is callout")
+    callout = blocks[0]["callout"]
+    _assert(callout["icon"] == {"type": "emoji", "emoji": "ℹ️"}, "NOTE icon is ℹ️")
+    _assert(callout["color"] == "blue_background", "NOTE color is blue_background")
+    body_text = "".join(s["text"]["content"] for s in callout["rich_text"])
+    _assert("This is a note." in body_text, "body line 1 preserved")
+    _assert("Spans multiple lines." in body_text, "body line 2 preserved")
+
+
+def test_callout_tip():
+    blocks = markdown_to_notion_blocks("> [!TIP]\n> Use this trick.")
+    _assert(blocks[0]["type"] == "callout", "TIP block is callout")
+    _assert(blocks[0]["callout"]["icon"]["emoji"] == "💡", "TIP icon is 💡")
+    _assert(blocks[0]["callout"]["color"] == "green_background", "TIP color is green")
+
+
+def test_callout_important():
+    blocks = markdown_to_notion_blocks("> [!IMPORTANT]\n> Read this.")
+    _assert(blocks[0]["callout"]["icon"]["emoji"] == "☝️", "IMPORTANT icon is ☝️")
+    _assert(blocks[0]["callout"]["color"] == "purple_background", "IMPORTANT color is purple")
+
+
+def test_callout_warning():
+    blocks = markdown_to_notion_blocks("> [!WARNING]\n> Be careful.")
+    _assert(blocks[0]["callout"]["icon"]["emoji"] == "⚠️", "WARNING icon is ⚠️")
+    _assert(blocks[0]["callout"]["color"] == "yellow_background", "WARNING color is yellow")
+
+
+def test_callout_caution():
+    blocks = markdown_to_notion_blocks("> [!CAUTION]\n> Do not proceed.")
+    _assert(blocks[0]["callout"]["icon"]["emoji"] == "🚨", "CAUTION icon is 🚨")
+    _assert(blocks[0]["callout"]["color"] == "red_background", "CAUTION color is red")
+
+
+def test_callout_unknown_falls_through():
+    """An unrecognized alert type renders as a plain quote with the marker preserved."""
+    blocks = markdown_to_notion_blocks("> [!BOGUS]\n> some content")
+    _assert(blocks[0]["type"] == "quote", "unknown alert renders as quote, not callout")
+    quote_text = blocks[0]["quote"]["rich_text"][0]["text"]["content"]
+    _assert("[!BOGUS]" in quote_text, "[!BOGUS] marker preserved in quote text")
+
+
 def test_rich_text_anchor_link_becomes_bold():
     """TOC-style fragment links must not be sent as Notion link annotations."""
     spans = parse_rich_text("see [Section A](#section-a) below")
@@ -214,6 +260,12 @@ def run_all():
         test_blocks_todo,
         test_blocks_quote_code_divider,
         test_blocks_table,
+        test_callout_note,
+        test_callout_tip,
+        test_callout_important,
+        test_callout_warning,
+        test_callout_caution,
+        test_callout_unknown_falls_through,
         test_rich_text_anchor_link_becomes_bold,
         test_rich_text_relative_link_becomes_plain,
         test_rich_text_absolute_link_preserved,