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

cmd/mavend/wipe.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"io"
+
+	"github.com/kami/maven/internal/store"
+)
+
+// runWipe implements the -wipe flag: it prints what the database holds, and
+// removes it only when the operator also passed -confirm-wipe (Vikunja #494).
+//
+// Two flags rather than one, because the destructive reading of a single flag
+// is the reading a mistyped command gets. Without the confirmation this is a
+// dry run that costs nothing and answers the question a QA session actually
+// has — what is on this box right now.
+//
+// It runs before any daemon component is wired, so nothing is writing while
+// the tables go. The daemon exits afterwards rather than serving a store it
+// just emptied, because every component that read the old rows at boot would
+// still be holding them.
+func runWipe(ctx context.Context, st *store.Store, out io.Writer, confirmed bool) error {
+	counts, err := st.WipeCounts(ctx)
+	if err != nil {
+		return fmt.Errorf("wipe: read counts: %w", err)
+	}
+	total := 0
+	for _, c := range counts {
+		total += c.Rows
+		fmt.Fprintf(out, "  %-24s %d\n", c.Table, c.Rows)
+	}
+	fmt.Fprintf(out, "  %-24s %d rows in %d tables\n", "TOTAL", total, len(counts))
+
+	if !confirmed {
+		fmt.Fprintln(out, "\nnothing was deleted. pass -confirm-wipe to delete all of it.")
+		fmt.Fprintln(out, "config, models, passkeys and the encryption key are files and are never touched.")
+		return nil
+	}
+	if err := st.Wipe(ctx); err != nil {
+		return err
+	}
+	fmt.Fprintf(out, "\nwiped. %d rows gone, the schema is intact, mavend knows nobody.\n", total)
+	return nil
+}