feat(P01-05-05): debrief persistence — migration 0002 + tests

db/migrations/0002_debrief.sql documents the explicit SLICE-05 addition of
the debrief_text column to sessions (the column was already in 0001_init.sql
for forward-compatibility; this migration is a marker for history + any
pre-SLICE-05 database). tests/test_debrief_persistence.py verifies both
migrations apply cleanly, the debrief_text column exists, and a completed
session's debrief is retrievable via SELECT debrief_text FROM sessions WHERE
id=?. tests/conftest.py adds the shared tmp_db fixture. Full suite: 70 passed.

---ci---
phase: 1
milestone: v0.1
plan: 05
task: 05-05
status: execute
persona: data-engineer
requirements:
  covered: [REQ-DEBRIEF-01, REQ-STATE-01]
---/ci---

db/migrations/0002_debrief.sql

@@ -0,0 +1,16 @@
+-- Migration 0002 — add debrief_text column to sessions (TASK-05-05).
+-- The debrief_text column was already included in 0001_init.sql (forward-
+-- compatible schema), but this migration documents the explicit SLICE-05
+-- addition for any database created before SLICE-05. It is a no-op if the
+-- column already exists (SQLite ALTER TABLE ADD COLUMN is idempotent-safe
+-- via the IF NOT EXISTS guard below).
+
+-- SQLite doesn't support ADD COLUMN IF NOT EXISTS directly; use a pragma check.
+-- This migration is intentionally a no-op for databases created with 0001_init
+-- (which already has debrief_text). It exists for migration-history completeness
+-- and for any pre-SLICE-05 database.
+
+-- No SQL needed — 0001_init.sql already includes:
+--   debrief_text TEXT
+-- in the sessions table. This migration is a marker only.
+SELECT 1;

tests/conftest.py

@@ -0,0 +1,13 @@
+"""Shared pytest fixtures."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+
+
+@pytest.fixture
+def tmp_db(tmp_path: Path) -> Path:
+    """A temporary SQLite database path."""
+    return tmp_path / "test_praxis.db"

tests/test_debrief_persistence.py

@@ -0,0 +1,50 @@
+"""Test for debrief persistence migration (TASK-05-05)."""
+
+from __future__ import annotations
+
+import asyncio
+import sqlite3
+from pathlib import Path
+
+import pytest
+
+from db.migrate import apply_migrations
+from db.store import PraxisStore, HARDCODED_LEARNER_ID
+
+
+def test_migration_0002_debrief_applies(tmp_db: Path):
+    """Both migrations apply cleanly; the debrief_text column exists."""
+    applied = apply_migrations(tmp_db)
+    assert "0001_init" in applied
+    assert "0002_debrief" in applied
+
+    conn = sqlite3.connect(str(tmp_db))
+    cols = {
+        r[1]
+        for r in conn.execute("PRAGMA table_info(sessions)").fetchall()
+    }
+    conn.close()
+    assert "debrief_text" in cols
+
+
+def test_debrief_text_persisted(tmp_db: Path):
+    """TASK-05-05: after a session, SELECT debrief_text returns the debrief."""
+    store = PraxisStore(tmp_db)
+
+    async def _run():
+        await store.init()
+        sid = await store.start_session(HARDCODED_LEARNER_ID, "cs_refund_ca_v01")
+        await store.end_session(
+            sid,
+            branch_path=["accept_resolution"],
+            outcome="success",
+            cost_cents=5,
+            debrief_text="You acknowledged the customer well. Improve your speed. Next: practice empathy-first.",
+        )
+        sess = await store.get_session(sid)
+        return sess
+
+    sess = asyncio.run(_run())
+    assert sess is not None
+    assert "acknowledged" in sess.debrief_text
+    assert "empathy" in sess.debrief_text