Implement CLI commands and utility functions for MVP-1

- Add complete CLI command implementations with Typer subcommands
- Implement utils/time.py with duration formatting and datetime utilities
- Implement utils/path.py with project path management utilities
- Wire up all commands to main CLI entry point

tracker/utils/time.py

@@ -1 +1,91 @@
 """Time utility functions."""
+
+from datetime import datetime, timedelta
+
+
+def format_duration(minutes: int) -> str:
+    """Format duration in minutes to human-readable string.
+
+    Args:
+        minutes: Duration in minutes.
+
+    Returns:
+        Human-readable duration string (e.g., "1h 30m", "45m").
+    """
+    if minutes < 60:
+        return f"{minutes}m"
+    hours = minutes // 60
+    remaining_minutes = minutes % 60
+    if remaining_minutes == 0:
+        return f"{hours}h"
+    return f"{hours}h {remaining_minutes}m"
+
+
+def parse_duration(duration_str: str) -> int:
+    """Parse duration string to minutes.
+
+    Args:
+        duration_str: Duration string like "1h 30m", "45m", "2h".
+
+    Returns:
+        Duration in minutes.
+    """
+    total_minutes = 0
+    duration_str = duration_str.lower().strip()
+
+    # Parse hours
+    if "h" in duration_str:
+        parts = duration_str.split()
+        for part in parts:
+            if "h" in part:
+                total_minutes += int(part.replace("h", "")) * 60
+            elif "m" in part:
+                total_minutes += int(part.replace("m", ""))
+
+    # If no hours, try just minutes
+    if total_minutes == 0 and "m" in duration_str:
+        total_minutes = int(duration_str.replace("m", ""))
+    elif total_minutes == 0:
+        try:
+            total_minutes = int(duration_str)
+        except ValueError:
+            return 0
+
+    return total_minutes
+
+
+def is_recent(dt: datetime, hours: int = 24) -> bool:
+    """Check if a datetime is within the specified hours.
+
+    Args:
+        dt: Datetime to check.
+        hours: Number of hours to consider as "recent".
+
+    Returns:
+        True if dt is within the specified hours.
+    """
+    return datetime.now() - dt < timedelta(hours=hours)
+
+
+def format_datetime(dt: datetime) -> str:
+    """Format datetime to standard string.
+
+    Args:
+        dt: Datetime to format.
+
+    Returns:
+        Formatted string in YYYY-MM-DD HH:MM format.
+    """
+    return dt.strftime("%Y-%m-%d %H:%M")
+
+
+def format_date(dt: datetime) -> str:
+    """Format datetime to date string.
+
+    Args:
+        dt: Datetime to format.
+
+    Returns:
+        Formatted string in YYYY-MM-DD format.
+    """
+    return dt.strftime("%Y-%m-%d")