docs(milestone): merge v0.3-mastery-scoring → main

v0.3 milestone merged to main. Mastery scoring + competency rubrics +
verifiable credentials (formative-tier) shipped. 13/13 REQ-IDs covered.
Next milestone: v0.4 (operator tier — cohort dashboard + auth + Postgres).

---ci---
project: praxis
phase: 2
milestone: v0.3
status: complete
milestone_complete: true
milestone_merged_to_main: true
---/ci---

server/paths/__init__.py

@@ -0,0 +1,18 @@
+"""Praxis path engine package (SLICE-05, REQ-PATH-02).
+
+Defines the 6-week competency path structure with mastery gates (D-037),
+loaded from YAML into typed Pydantic models and driven by the path engine.
+"""
+
+from __future__ import annotations
+
+from server.paths.schema import Path, PathWeek, WeekGate, ValidationError
+from server.paths.engine import PathEngine
+
+__all__ = [
+    "Path",
+    "PathWeek",
+    "WeekGate",
+    "PathEngine",
+    "ValidationError",
+]