fix(parser): allow blank lines within a table block

Blank (whitespace-only) lines inside a table no longer split it into
separate blocks. They are buffered and discarded if more table rows
follow, enabling patterns like pre-filling a recurring meeting entry
with a blank line separating it from the rest of the day's entries.

src/timesheets/parser.py

@@ -38,21 +38,31 @@ def extract_table_blocks(lines: list[str]) -> list[list[str]]:
     """
     Split a markdown document into contiguous table blocks.
 
-    A block is a maximal run of lines that are either table rows or table
-    separators. Non-table lines (headings, prose, bullet points, blank lines)
-    break a block. Each returned block contains at least a header and a
-    separator line; shorter runs are discarded.
+    A block is a maximal run of table rows/separators, with blank (whitespace-
+    only) lines tolerated in the middle as long as more table rows follow.
+    Non-table, non-blank lines always break a block.
+    Each returned block contains at least a header and a separator line;
+    shorter runs are discarded.
     """
     blocks: list[list[str]] = []
     current: list[str] = []
+    pending_blanks: list[str] = []  # blank lines seen after last table row
 
     for line in lines:
         if _is_table_line(line):
+            # Resume block, discarding the pending blanks (they were internal)
+            pending_blanks.clear()
             current.append(line)
+        elif not line.strip():
+            # Blank line — buffer it; don't break the block yet
+            if current:
+                pending_blanks.append(line)
         else:
-            if len(current) >= 2:  # at minimum: header + separator
+            # Non-table, non-blank line — close any open block
+            if len(current) >= 2:
                 blocks.append(current)
             current = []
+            pending_blanks.clear()
 
     if len(current) >= 2:
         blocks.append(current)