Add ~ marker to exclude entries from CSV export

Prefix the project name or note column with ~ to mark an entry as
count-but-don't-export. Marked entries are included in summary and
status totals but omitted from all csv output (both --raw and
aggregated, single-day and weekly).

  | 09:00 | 17:00 | 8:00 | ~Leave |  | Day off  |
  | 09:00 | 17:00 | 8:00 |  Leave |  | ~Day off |

The ~ is stripped from whichever field carries it before any
downstream processing, so project map resolution is unaffected.

Implementation:
- parse_table sets skip_csv=True on marked rows and strips the ~
- new filter_skip_csv() helper in parser.py
- to_csv_entries() skips skip_csv rows
- _cmd_csv calls filter_skip_csv() before aggregate_rows()

src/timesheets/cli.py

@@ -27,6 +27,7 @@ from .output import (
 from .parser import (
     aggregate_rows,
     filter_rows_by_date,
+    filter_skip_csv,
     filter_week_sections,
     parse_document,
     resolve_overlaps,
@@ -436,7 +437,9 @@ def _cmd_csv(args: argparse.Namespace, config: dict) -> None:
         day_sections = [
             (
                 _fmt(day),
-                to_csv_entries(rows) if args.raw else aggregate_rows(rows),
+                to_csv_entries(rows)
+                if args.raw
+                else aggregate_rows(filter_skip_csv(rows)),
             )
             for day, rows in day_sections_raw
         ]
@@ -450,7 +453,9 @@ def _cmd_csv(args: argparse.Namespace, config: dict) -> None:
         rows = _resolve_rows(args, config, target_date)
         if not rows:
             print("Warning: no timesheet rows found in input.", file=sys.stderr)
-        entries = to_csv_entries(rows) if args.raw else aggregate_rows(rows)
+        entries = (
+            to_csv_entries(rows) if args.raw else aggregate_rows(filter_skip_csv(rows))
+        )
         if args.output:
             with open(args.output, "w", newline="", encoding="utf-8") as f:
                 write_csv(entries, f, _fmt(target_date), project_map)

src/timesheets/output.py

@@ -27,7 +27,7 @@ def to_csv_entries(rows: list[dict]) -> list[dict]:
             "quantity": row["duration_hours"],
         }
         for row in rows
-        if row["duration_hours"] is not None
+        if row["duration_hours"] is not None and not row.get("skip_csv")
     ]
 
 

src/timesheets/parser.py

@@ -103,6 +103,19 @@ def parse_table(lines: list[str], has_duration_col: bool = True) -> list[dict]:
             note = strip_markdown_link(cells[4])
             duration = None
 
+        project_stripped = project.strip()
+        if project_stripped.startswith("~"):
+            skip_csv = True
+            project = project_stripped[1:].strip()
+        else:
+            skip_csv = False
+            project = project_stripped
+
+        note_stripped = note.strip()
+        if note_stripped.startswith("~"):
+            skip_csv = True
+            note = note_stripped[1:].strip()
+
         if start.lower() == "start":
             continue
         if not re.match(r"^\d+:\d{2}$", start):
@@ -112,17 +125,18 @@ def parse_table(lines: list[str], has_duration_col: bool = True) -> list[dict]:
         if not re.match(r"^\d+:\d{2}$", end):
             if duration is None:
                 # No end and no duration — preserve as an open entry
-                rows.append(
-                    {
-                        "start": start,
-                        "end": None,
-                        "duration_hours": None,
-                        "project": project,
-                        "story": story,
-                        "story_raw": story_raw,
-                        "note": note,
-                    }
-                )
+                row = {
+                    "start": start,
+                    "end": None,
+                    "duration_hours": None,
+                    "project": project,
+                    "story": story,
+                    "story_raw": story_raw,
+                    "note": note,
+                }
+                if skip_csv:
+                    row["skip_csv"] = True
+                rows.append(row)
             continue
 
         if duration is not None:
@@ -135,17 +149,18 @@ def parse_table(lines: list[str], has_duration_col: bool = True) -> list[dict]:
             except ValueError:
                 continue
 
-        rows.append(
-            {
-                "start": start,
-                "end": end,
-                "duration_hours": duration_hours,
-                "project": project,
-                "story": story,
-                "story_raw": story_raw,
-                "note": note,
-            }
-        )
+        row = {
+            "start": start,
+            "end": end,
+            "duration_hours": duration_hours,
+            "project": project,
+            "story": story,
+            "story_raw": story_raw,
+            "note": note,
+        }
+        if skip_csv:
+            row["skip_csv"] = True
+        rows.append(row)
 
     return rows
 
@@ -354,6 +369,11 @@ def resolve_overlaps(rows: list[dict]) -> list[dict]:
     return open_entries + closed
 
 
+def filter_skip_csv(rows: list[dict]) -> list[dict]:
+    """Return a copy of rows with any skip_csv-marked entries removed."""
+    return [r for r in rows if not r.get("skip_csv")]
+
+
 def build_description(story: str, note: str) -> str:
     """Combine story and note into a single description string."""
     parts = [p.strip() for p in [story, note] if p.strip()]