wipe: one command empties the box and leaves it standing (V-494)

There was no documented way to repair a poisoned box. Two invented facts
written during QA disabled world answering for every later turn (V-470), and
revert voids the SQL row while leaving the vector behind (V-493). This is the
operation that undoes both.

Store.Wipe drops every table sqlite_master reports and rebuilds from schema.sql
plus the migrations, rather than deleting from a hand-written list. A list has
to be edited whenever a table is added, and the once it is not, the wipe leaves
personal data behind while reporting success. It vacuums afterwards, because
free pages still hold readable text.

mavend -wipe prints every table and its row count and exits. That alone is a
dry run and answers what a QA session actually asks: what is on this box. It
deletes only with -confirm-wipe. Two flags, because the destructive reading of
one flag is the reading a mistyped command gets.

Nothing outside the database moves. Config, models, passkeys.json and the
encryption key are files.

QA isolation and onboarding are the other two thirds of V-494 and are not here.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SoL7EBdYC5Mhz3DJd49GJy

internal/store/wipe_test.go

@@ -0,0 +1,99 @@
+package store
+
+import (
+	"context"
+	"database/sql"
+	"path/filepath"
+	"testing"
+	"time"
+)
+
+// A wipe has to leave a working, empty install: every table still there, every
+// migration still applied, and not one row of his anywhere (Vikunja #494).
+func TestWipeEmptiesEveryTableAndLeavesTheSchemaUsable(t *testing.T) {
+	ctx := context.Background()
+	path := filepath.Join(t.TempDir(), "wipe.db")
+	s, err := Open(ctx, path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer s.Close()
+
+	now := time.Now()
+	if _, err := s.WriteFact(ctx, now, KindSelf, "monitor", "новый", "tap:test", 1, sql.NullInt64{}); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := s.WriteNote(ctx, now, "купил монитор", []float32{0.1, 0.2}, "tap:test"); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := s.CaptureTask(ctx, Task{Text: "вернуть монитор", Source: "tap:test", Status: TaskOpen, CreatedTs: now}); err != nil {
+		t.Fatal(err)
+	}
+
+	before, err := s.WipeCounts(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	populated := 0
+	for _, c := range before {
+		if c.Rows > 0 {
+			populated++
+		}
+	}
+	if populated == 0 {
+		t.Fatal("nothing was written, so the wipe proves nothing")
+	}
+
+	if err := s.Wipe(ctx); err != nil {
+		t.Fatal(err)
+	}
+
+	after, err := s.WipeCounts(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(after) != len(before) {
+		t.Errorf("table count changed across the wipe: %d before, %d after", len(before), len(after))
+	}
+	for _, c := range after {
+		if c.Rows != 0 {
+			t.Errorf("table %s still holds %d rows after the wipe", c.Table, c.Rows)
+		}
+	}
+
+	// The migrations are what make the schema usable, so the check that matters
+	// is a write through the newest columns, not a version number.
+	if _, err := s.CaptureTask(ctx, Task{Text: "новая задача", Source: "tap:test", Status: TaskOpen, CreatedTs: now}); err != nil {
+		t.Errorf("the store is not usable after a wipe: %v", err)
+	}
+	if _, err := s.WriteFact(ctx, now, KindSelf, "monitor", "другой", "tap:test", 1, sql.NullInt64{}); err != nil {
+		t.Errorf("the store is not usable after a wipe: %v", err)
+	}
+}
+
+// A wipe that reports success while leaving a table behind is the failure the
+// drop-everything approach exists to prevent, so the count has to see the
+// tables migrations added, not only the ones schema.sql declares.
+func TestWipeCountsSeeMigratedTables(t *testing.T) {
+	ctx := context.Background()
+	s, err := Open(ctx, filepath.Join(t.TempDir(), "counts.db"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer s.Close()
+
+	counts, err := s.WipeCounts(ctx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	seen := map[string]bool{}
+	for _, c := range counts {
+		seen[c.Table] = true
+	}
+	// One from schema.sql, three from migrations, one from a table rebuild.
+	for _, want := range []string{"facts", "memory_vectors", "tasks", "ecosystem_traces", "nudges"} {
+		if !seen[want] {
+			t.Errorf("wipe does not see table %s", want)
+		}
+	}
+}