Crt, Ripple and Glitch take a level, 0 to 3, tunable at run time

Coordinator's request: `Crt 0..3` (likewise Ripple, Glitch), 0 off, `on`
the default level 2 (the polished rewrite), `off` and a bare word as
before. The level is one uniform (pardesLevel, beside pardesOpaque in the
prefix's own block); each pass picks its constants by it. Level 3 is at
least as strong as the old effects, measured as pixels changed by more
than 8 in a channel against a plain frame: Crt 18.3% (old 17.4%), Ripple
11.1% (9.5%), Glitch 9.3% a frame (8.1%); Glitch's level raises how often
it bursts as well as how hard. Config and ctl report `Crt 2` / `Crt off`.

Shared files touched: ninep/ctl.zig (the report line). Not touched:
pardes.zig, Messages.zig, mouse.zig, gui.zig, detached/*.

1 files changed, 2 insertions, 1 deletions

diff --git a/test/output.zig b/test/output.zig
index 400e9508..0fdd9f4d 100644
--- a/test/output.zig
+++ b/test/output.zig
@@ -667,7 +667,8 @@ test "every enabled setting builtin mutates the State Config reports" {
     else
         "Panel transition unsupported\n";
     try std.testing.expect(std.mem.indexOf(u8, report, transition) != null);
-    const scene_status = if (builtins.capabilities.scene_shaders) "on" else "unsupported";
+    // A bare word turns a bundled pass on at its default level.
+    const scene_status = if (builtins.capabilities.scene_shaders) "2" else "unsupported";
     for ([_][]const u8{ "Crt", "Ripple", "Glitch" }) |name| {
         const line = try std.fmt.bufPrint(&buf, "{s} {s}\n", .{ name, scene_status });
         try std.testing.expect(std.mem.indexOf(u8, report, line) != null);