feat(db): shape_* columns on events (+ auto-migrate)

tests/test_shape_columns.py

@@ -0,0 +1,27 @@
+import sqlite3
+from sfm.database import SeismoDb
+
+_SHAPE_COLS = {"shape_crest_factor", "shape_near_peak_count",
+               "shape_sample_count", "shape_axis"}
+
+def _cols(db):
+    with sqlite3.connect(db.db_path) as c:
+        return {r[1] for r in c.execute("PRAGMA table_info(events)")}
+
+def test_fresh_db_has_shape_columns(tmp_path):
+    db = SeismoDb(tmp_path / "s.db")
+    assert _SHAPE_COLS <= _cols(db)
+
+def test_existing_db_migrates_shape_columns(tmp_path):
+    p = tmp_path / "s.db"
+    db = SeismoDb(p)
+    with sqlite3.connect(p) as c:      # simulate an older DB missing the columns
+        for col in _SHAPE_COLS:
+            c.execute(f"ALTER TABLE events DROP COLUMN {col}")
+    # sanity: dropped. Read via the already-constructed `db` (a raw PRAGMA
+    # read against db.db_path) rather than a fresh SeismoDb(p) — the latter
+    # would immediately re-trigger _migrate's self-healing ADD COLUMN loop
+    # and mask the gap we're trying to confirm.
+    assert not (_SHAPE_COLS <= _cols(db))
+    SeismoDb(p)                        # re-open triggers _migrate
+    assert _SHAPE_COLS <= _cols(SeismoDb(p))