test: remove trivial, duplicate and content-value tests (#2721)

## Summary
Many tests proved a specific change when it landed but don't need to run on every CI build forever. This removes **202 test methods and 9 files: 313 test cases, 2,247 → 1,934**. UOContent.Tests drops from about 14s to about 5s locally.

Removed:
- **Tautologies.** Asserting a constant, a constructor readback or a trivial getter, or testing BCL behavior.
- **Exact duplicates** of a surviving test on the same code path.
- **Obsolete regressions** whose failure can no longer be expressed.
- **Game-content values** shard owners customize (era drop rates, loot and skill tables, single-creature tuning). Each customization would otherwise force a test fix.

## How it was decided
1. Every test was classified, with a reason, by a per-shard sweep over all 287 test files.
2. Each proposed deletion was then checked by a second, adversarial reviewer against the surviving tests and the production code.
3. Anything that was the only coverage of a separate code path was **kept**, even where it looked like a duplicate. Examples: the unsigned `SpanReader`/`SpanWriter` methods, the at-location versus bounds enumerators, null-map enumerables, the security filters, archive-journal state transitions. About 130 proposed deletions were rejected this way.

Whole files removed:
- `FishingTests`, apart from 3 tests: the map-edge scan, serpent cleanup, and SOS chest consumption. The SOS test now stops at the first chest instead of measuring a catch rate. The multi-million-cast rate simulations are gone.
- `LordOaksTests` and `MeerEnragedTests` (single-creature tests).
- `AutoArchiveHelperTests`, `JsonDiscoverableTypeAttributeTests`, `DecimalSerializationTests` and `EnumConversionTests` (tautologies, or tests of their own local helpers).
- `NetworkStatsTests`.
- `MigratedDataLoadTests` (a subset of `AllSpawnFilesLoadTests`).
- `SpawnerFixtureCapture`: a capture tool, not a test, and its `version == 12` assert can no longer pass. The `.bin` fixtures it produced stay.

## Tests
- Server.Tests: 811 pass.
- UOContent.Tests: 1,123 pass.

A follow-up PR, stacked on this one, fixes how the remaining tests behave: shared state, CI-vacuous tests, harness duplication.

Projects/Server.Tests/Tests/Network/MovementThrottleTests.cs

@@ -212,30 +212,6 @@ public class MovementThrottleTests
         Assert.True(rate > 1.25f, $"Expected rate > 1.25, got {rate}");
     }
 
-    [Fact]
-    public void AnalyzeMovement_ModerateSpeedHack_ReturnsPossibleOrLikely()
-    {
-        // 8% faster than expected - moderate, should be Possible or Likely
-        var ns = CreateNetStateWithHistory(
-            (93, 100), (93, 100), (93, 100), (93, 100), (93, 100),
-            (93, 100), (93, 100), (93, 100), (93, 100), (93, 100)
-        );
-
-        // Set up stable, low-latency RTT (required for Likely verdict path)
-        ns._rttHistory = [50, 52, 48, 51, 49, 50, 51, 50];
-        ns._rttSampleCount = 8;
-        ns._rttVariance = 4; // Low variance
-
-        var verdict = MovementThrottle.AnalyzeMovement(ns, out var rate, out var sampleCount, out var confidence);
-
-        Assert.True(
-            verdict == MovementThrottle.DetectionVerdict.Possible ||
-            verdict == MovementThrottle.DetectionVerdict.Likely,
-            $"Expected Possible or Likely, got {verdict}. Rate={rate}, Confidence={confidence}"
-        );
-        Assert.True(rate > 1.05f && rate < 1.15f, $"Expected rate ~1.07, got {rate}");
-    }
-
     [Fact]
     public void AnalyzeMovement_BurstAfterLargeGap_ReducesConfidence()
     {
@@ -279,25 +255,6 @@ public class MovementThrottleTests
         Assert.Equal(MovementThrottle.DetectionVerdict.Definite, verdict);
     }
 
-    [Fact]
-    public void AnalyzeMovement_StableConnectionLowLatency_IncreasesConfidence()
-    {
-        var ns = CreateNetStateWithHistory(
-            (95, 100), (95, 100), (95, 100), (95, 100), (95, 100),
-            (95, 100), (95, 100), (95, 100), (95, 100), (95, 100)
-        );
-
-        // Set up stable, low-latency RTT
-        ns._rttHistory = [50, 52, 48, 51, 49, 50, 51, 50];
-        ns._rttSampleCount = 8;
-        ns._rttVariance = 4; // Low variance
-
-        var verdict = MovementThrottle.AnalyzeMovement(ns, out var rate, out var sampleCount, out var confidence);
-
-        // With stable connection, even small anomalies are more suspicious
-        Assert.True(confidence > 0.2f, $"Expected higher confidence for stable connection, got {confidence}");
-    }
-
     [Fact]
     public void AnalyzeMovement_UnstableConnection_ReducesConfidence()
     {