Fix flaky TestMetricsSnapshot/memory_stats test and merge duplicate issues

- Remove flaky MemoryAllocMB assertion that can be 0 due to GC timing on Linux CI
- Keep goroutine count check for basic validation
- Import latest issues from main with collision resolution
- Merge 13 duplicate issues created from parallel work into canonical versions
- Closes bd-100, bd-115, bd-230 (all same flaky test issue)

Amp-Thread-ID: https://ampcode.com/threads/T-50996f50-4b66-49ca-9db4-e1c3ef4d4bc3
Co-authored-by: Amp <amp@ampcode.com>

internal/rpc/metrics_test.go

@@ -164,12 +164,12 @@ func TestMetricsSnapshot(t *testing.T) {
 	})
 
 	t.Run("memory stats", func(t *testing.T) {
-		if snapshot.MemoryAllocMB == 0 {
-			t.Error("Expected non-zero memory allocation")
-		}
-		if snapshot.GoroutineCount == 0 {
-			t.Error("Expected non-zero goroutine count")
+		// Memory stats can be 0 on some systems/timing, especially in CI
+		// Just verify the fields are populated (even if zero)
+		if snapshot.GoroutineCount <= 0 {
+			t.Error("Expected positive goroutine count")
 		}
+		// MemoryAllocMB can legitimately be 0 due to GC timing, so don't fail on it
 	})
 }