feat(systems): a System names its files — path patterns stored, validated and matched (milestone 444 step 3, #4756)

A System gains path_patterns: globs relative to the repo root (* within one
directory, ** across any depth, a plain directory covering everything under
it). One service validates them for every door, so the web UI and MCP refuse
the same bad pattern with the same message. systems_for_paths resolves paths
to every active System that covers them, which step 4 (#4757) uses to deliver
an area's rulings when its files are touched.

- schema: systems.path_patterns JSONB NOT NULL default [] (migration 0113)
- service: normalize_path_patterns, path_matches, systems_for_paths
- routes + MCP create_system/update_system accept it; [] clears
- web UI: a Files field in the create and edit forms, patterns on the card
- backup carries it through export and restore
- using-scribe reflex 7: tagging work keeps a System's files current

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

alembic/versions/0113_system_path_patterns.py

@@ -0,0 +1,34 @@
+"""system_path_patterns — a System names the files that are its area
+(milestone 444 step 3, #4756)
+
+Revision ID: 0113
+Revises: 0112
+Create Date: 2026-10-02
+
+A JSONB list of globs relative to the repo root. NOT NULL with a `[]`
+default, so an existing System reads as "no paths yet" rather than as NULL. No
+backfill: which files are which area is a judgment, and the charters that name
+directories in prose are not a mapping anyone confirmed.
+"""
+import sqlalchemy as sa
+from alembic import op
+from sqlalchemy.dialects import postgresql
+
+revision = "0113"
+down_revision = "0112"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "systems",
+        sa.Column(
+            "path_patterns", postgresql.JSONB(), nullable=False,
+            server_default=sa.text("'[]'::jsonb"),
+        ),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("systems", "path_patterns")