milestone 28: query provenance — every logged query is exactly explainable

query rows gain qclass, rcode, group, policy action and reason, the
matched rule or list entry with its source, cname and safe-search
targets, route kind, forward zone, and the resolver that actually
answered — the pool and local markers die. servfails are logged and
name the resolver that lost; post-parse protocol refusals become rows.
a detail page at /queries/:id renders the ordered explanation, and
coverage watermarks distinguish an empty history from a missing one.

the schema fingerprint changes: existing query history is recreated
with the old file kept aside and the reset filed as a resolved
diagnostic. fixes an oversized udp reply being rebuilt as noerror,
which handed clients a truncated nxdomain as success.

src/web/routes.zig

@@ -67,6 +67,10 @@ pub const table: []const router.RouteInfo = &.{
     // Query log, stats, live stream, lookup.
     .{ .method = .GET, .pattern = "/api/queries", .auth = .session, .policy = .read, .handler = queries.list },
     .{ .method = .GET, .pattern = "/api/queries/live", .auth = .session, .policy = .read, .handler = live.stream, .rate_limit = .exempt },
+    // Listed after the literal `live`, which a linear first-match scan reaches
+    // first — though `{id}` would refuse it anyway, since it captures a
+    // positive integer and nothing else.
+    .{ .method = .GET, .pattern = "/api/queries/{id}", .auth = .session, .policy = .read, .handler = queries.detail },
     .{ .method = .GET, .pattern = "/api/stats", .auth = .session, .policy = .read, .handler = stats.totals },
     .{ .method = .GET, .pattern = "/api/stats/timeseries", .auth = .session, .policy = .read, .handler = stats.timeseries },
     .{ .method = .GET, .pattern = "/api/lookup", .auth = .session, .policy = .read, .handler = lookup.handle },
@@ -152,7 +156,7 @@ const std = @import("std");
 const testing = std.testing;
 
 test "the table carries every endpoint of the milestone" {
-    try testing.expectEqual(@as(usize, 60), table.len);
+    try testing.expectEqual(@as(usize, 61), table.len);
 }
 
 test "no two entries claim the same method and pattern" {