fix: neutral hint form for remaining client-facing tool mentions, Limits bounds accessor

Fix round 1 (task 10 review):
- FieldValidator's "unknown field" validation error (reaches the
  client via validation_failed's fields) and PostPresenter's
  DIVI_HINT (surfaced in the result's hints array) still named
  lit-content-types/lit-content-update as plain lit-<name>; converted
  both to the neutral "lit/<name> (direkt: lit-<name>)" form like the
  other hints from task 10. Re-grepped src/ for any other client-facing
  error/field/hints text naming a direct-by-default tool as lit-<name>
  (descriptions/schemas excluded per Q11c) - none left.
- Added Limits::bounds() (field => [min, max]) and made LimitsTab use
  it for the number inputs' min/max instead of a second, hardcoded
  copy of the same bounds.
- LimitsTab now shows a description note when the configured upload_mb
  exceeds wp_max_upload_size() (PHP's upload_max_filesize/post_max_size),
  since WordPress would refuse a larger upload before this limit ever
  applies.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7

tests/Unit/LimitsTest.php

@@ -42,4 +42,23 @@ final class LimitsTest extends TestCase
         );
         self::assertSame(Limits::DEFAULTS, Limits::sanitize(null));
     }
+
+    public function testBoundsMatchesWhatSanitizeClampsTo(): void
+    {
+        self::assertSame([1, 100], Limits::bounds()['upload_mb']);
+        self::assertSame([1, 3650], Limits::bounds()['log_retention_days']);
+        self::assertSame([1, 100], Limits::bounds()['snapshot_count']);
+
+        // Cross-check against sanitize()'s actual clamping, so the two can't drift apart.
+        $tooLow = array_map(static fn (array $bound): int => $bound[0] - 1, Limits::bounds());
+        $tooHigh = array_map(static fn (array $bound): int => $bound[1] + 1, Limits::bounds());
+        self::assertSame(
+            array_map(static fn (array $bound): int => $bound[0], Limits::bounds()),
+            Limits::sanitize($tooLow)
+        );
+        self::assertSame(
+            array_map(static fn (array $bound): int => $bound[1], Limits::bounds()),
+            Limits::sanitize($tooHigh)
+        );
+    }
 }