Implement storage layer for MVP-1 Personal Tracker CLI

Add storage layer with FileStorage, MarkdownReader, and MarkdownWriter classes.
Add data models (Project, Session, Note, Change).

tracker/services/heuristics_service.py

@@ -0,0 +1,47 @@
+"""Heuristics service for suggestions based on rules."""
+
+from datetime import datetime
+
+from ..models import Session, Project
+
+
+def suggest_next_steps(session: Session, project: Project) -> list[str]:
+    """
+    Generate suggestions based on session state and project context.
+    Rules:
+    - si hay blockers abiertos, sugerir "Destrabar: [bloqueos]"
+    - si hay changes sin references, sugerir "Validar cambios recientes"
+    - si work_done está vacío y session > 30 min, sugerir "Revisar progreso del objetivo"
+    - si no hay next_steps definidos, sugerir "Definir próximos pasos"
+    """
+    suggestions = []
+
+    # Rule: blockers open
+    if session.blockers:
+        for blocker in session.blockers:
+            suggestions.append(f"Destrabar: {blocker}")
+
+    # Rule: changes without references
+    changes_without_refs = []
+    for change in session.changes:
+        # Simple heuristic: if change doesn't reference anything specific
+        if change and not any(ref in change.lower() for ref in ["#", "commit", "pr", "issue"]):
+            changes_without_refs.append(change)
+
+    if changes_without_refs:
+        suggestions.append("Validar cambios recientes")
+
+    # Rule: work_done empty and session > 30 minutes
+    if not session.work_done:
+        duration = session.duration_minutes
+        if duration == 0 and session.ended_at and session.started_at:
+            duration = int((session.ended_at - session.started_at).total_seconds() / 60)
+
+        if duration > 30:
+            suggestions.append("Revisar progreso del objetivo")
+
+    # Rule: no next_steps defined
+    if not session.next_steps:
+        suggestions.append("Definir próximos pasos")
+
+    return suggestions