store: migration 0009 — admin-creds kind + host_repo_stats

internal/store/migrations/0009_admin_creds_and_repo_stats.sql

@@ -0,0 +1,58 @@
+-- 0009_admin_creds_and_repo_stats.sql
+--
+-- Phase 5 of the P2 redesign needs two things in the schema:
+--
+-- 1. A second credential row per host. Today host_credentials is
+--    1:1 with hosts. For prune (and any future destructive op) we
+--    want a rest-server admin user whose password gives delete
+--    access — separate from the append-only user used on every
+--    backup. Add a `kind` column with default 'repo'; existing rows
+--    become kind='repo'. Future admin rows live alongside.
+--
+-- 2. A small singleton-per-host projection for repo size, snapshot
+--    count, last-prune freed bytes, lock state, and last-check
+--    result. Backed by `restic stats --json` + sniffed `restic
+--    check` stderr.
+--
+-- Use column-level ALTERs only; host_credentials has no inbound
+-- FKs but the rule from CLAUDE.md still applies.
+
+ALTER TABLE host_credentials ADD COLUMN kind TEXT NOT NULL DEFAULT 'repo';
+
+-- The PK on host_credentials is currently (host_id) — we need a
+-- composite (host_id, kind). SQLite has no ALTER TABLE …
+-- ADD/CHANGE PRIMARY KEY, so this is the one place a rebuild is
+-- justified. host_credentials has no inbound FKs, so the cascade
+-- trap doesn't apply here. Verified against schema/0002.
+
+CREATE TABLE host_credentials_new (
+  host_id        TEXT NOT NULL REFERENCES hosts(id) ON DELETE CASCADE,
+  kind           TEXT NOT NULL DEFAULT 'repo'
+                   CHECK (kind IN ('repo', 'admin')),
+  enc_repo_creds TEXT NOT NULL,
+  updated_at     TEXT NOT NULL,
+  PRIMARY KEY (host_id, kind)
+);
+INSERT INTO host_credentials_new (host_id, kind, enc_repo_creds, updated_at)
+  SELECT host_id, kind, enc_repo_creds, updated_at FROM host_credentials;
+DROP TABLE host_credentials;
+ALTER TABLE host_credentials_new RENAME TO host_credentials;
+
+-- Repo stats projection. One row per host, upserted by the agent's
+-- stats.report envelope (which fires after every successful backup
+-- and after every check / prune). All fields nullable so a freshly
+-- enrolled host with no jobs yet is representable.
+
+CREATE TABLE host_repo_stats (
+  host_id                 TEXT PRIMARY KEY REFERENCES hosts(id) ON DELETE CASCADE,
+  total_size_bytes        INTEGER,
+  raw_size_bytes          INTEGER,
+  unique_files            INTEGER,
+  snapshot_count          INTEGER,
+  last_check_at           TEXT,
+  last_check_status       TEXT, -- 'ok' | 'errors_found' | 'failed'
+  lock_present            INTEGER NOT NULL DEFAULT 0,
+  last_prune_at           TEXT,
+  last_prune_freed_bytes  INTEGER,
+  updated_at              TEXT NOT NULL
+);

internal/store/store_test.go

@@ -84,6 +84,55 @@ func TestMigrateIsIdempotent(t *testing.T) {
 	}
 }
 
+func TestMigration0009Schema(t *testing.T) {
+	t.Parallel()
+	s := openTestStore(t)
+	ctx := context.Background()
+
+	// host_credentials must have a composite PK (host_id, kind).
+	// We verify this by inserting two rows for the same host_id (different kinds)
+	// and confirming a duplicate (host_id, kind) fails.
+	_, err := s.DB().ExecContext(ctx,
+		`INSERT INTO hosts (id, name, os, arch, enrolled_at) VALUES (?,?,?,?,?)`,
+		"h-0009", "test-host", "linux", "amd64", "2026-01-01T00:00:00Z")
+	if err != nil {
+		t.Fatalf("insert host: %v", err)
+	}
+	now := "2026-01-01T00:00:00Z"
+	if _, err := s.DB().ExecContext(ctx,
+		`INSERT INTO host_credentials (host_id, kind, enc_repo_creds, updated_at) VALUES (?,?,?,?)`,
+		"h-0009", "repo", "enc-repo", now); err != nil {
+		t.Fatalf("insert repo creds: %v", err)
+	}
+	if _, err := s.DB().ExecContext(ctx,
+		`INSERT INTO host_credentials (host_id, kind, enc_repo_creds, updated_at) VALUES (?,?,?,?)`,
+		"h-0009", "admin", "enc-admin", now); err != nil {
+		t.Fatalf("insert admin creds: %v", err)
+	}
+	// Duplicate (host_id, kind) must fail.
+	if _, err := s.DB().ExecContext(ctx,
+		`INSERT INTO host_credentials (host_id, kind, enc_repo_creds, updated_at) VALUES (?,?,?,?)`,
+		"h-0009", "repo", "enc-repo-2", now); err == nil {
+		t.Fatal("expected unique constraint violation on (host_id, kind), got nil")
+	}
+
+	// host_repo_stats table must exist with expected columns.
+	if _, err := s.DB().ExecContext(ctx,
+		`INSERT INTO host_repo_stats (host_id, lock_present, updated_at) VALUES (?,?,?)`,
+		"h-0009", 0, now); err != nil {
+		t.Fatalf("insert host_repo_stats: %v", err)
+	}
+	var lockPresent int
+	if err := s.DB().QueryRowContext(ctx,
+		`SELECT lock_present FROM host_repo_stats WHERE host_id = ?`, "h-0009",
+	).Scan(&lockPresent); err != nil {
+		t.Fatalf("select host_repo_stats: %v", err)
+	}
+	if lockPresent != 0 {
+		t.Errorf("expected lock_present=0, got %d", lockPresent)
+	}
+}
+
 func TestForeignKeysEnforced(t *testing.T) {
 	t.Parallel()
 	s := openTestStore(t)