feat(infra): add repository implementations, mappers, FastAPI wiring, and technique indexes

backend/alembic/versions/b026_add_technique_query_indexes.py

@@ -0,0 +1,38 @@
+"""add_technique_query_indexes
+
+Add indexes on techniques table for common query patterns
+(filter by tactic, filter by status_global) used in heatmap, scoring,
+and list-all-techniques operations.
+
+These may already exist if the ORM model auto-created them; the
+``if_not_exists`` flag makes this migration safe to run regardless.
+
+Revision ID: b026techidx
+Revises: b025uqtdr
+Create Date: 2026-02-18 18:00:00.000000
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+
+revision: str = "b026techidx"
+down_revision: Union[str, None] = "b025uqtdr"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.execute(
+        "CREATE INDEX IF NOT EXISTS ix_techniques_tactic "
+        "ON techniques (tactic)"
+    )
+    op.execute(
+        "CREATE INDEX IF NOT EXISTS ix_techniques_status_global "
+        "ON techniques (status_global)"
+    )
+
+
+def downgrade() -> None:
+    op.drop_index("ix_techniques_status_global", table_name="techniques")
+    op.drop_index("ix_techniques_tactic", table_name="techniques")