test: remove redundant tests

Remove integration tests in config_extended_test.go that duplicate
unit tests in config_test.go for findLocalCheatpath. Remove redundant
fuzz functions (FuzzFindLocalCheatpathNearestWins, FuzzTagsStress),
a duplicate parse test (TestParseInvalidYAML), and a permanently-skipped
interactive test (TestPromptIntegration).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/sheets/tags_fuzz_test.go

@@ -127,64 +127,3 @@ func FuzzTags(f *testing.F) {
 		}()
 	})
 }
-
-// FuzzTagsStress tests Tags function with large numbers of tags
-func FuzzTagsStress(f *testing.F) {
-	// Seed: number of unique tags, number of sheets, tags per sheet
-	f.Add(10, 10, 5)
-	f.Add(100, 50, 10)
-	f.Add(1000, 100, 20)
-
-	f.Fuzz(func(t *testing.T, numUniqueTags int, numSheets int, tagsPerSheet int) {
-		// Limit to reasonable values
-		if numUniqueTags > 1000 || numUniqueTags < 0 ||
-			numSheets > 1000 || numSheets < 0 ||
-			tagsPerSheet > 100 || tagsPerSheet < 0 {
-			t.Skip("Skipping unreasonable test case")
-		}
-
-		// Generate unique tags
-		uniqueTags := make([]string, numUniqueTags)
-		for i := 0; i < numUniqueTags; i++ {
-			uniqueTags[i] = "tag" + string(rune(i))
-		}
-
-		// Create sheets with random tags
-		cheatpaths := []map[string]sheet.Sheet{
-			make(map[string]sheet.Sheet),
-		}
-
-		for i := 0; i < numSheets; i++ {
-			// Select random tags for this sheet
-			sheetTags := make([]string, 0, tagsPerSheet)
-			for j := 0; j < tagsPerSheet && j < numUniqueTags; j++ {
-				// Distribute tags across sheets
-				tagIndex := (i*tagsPerSheet + j) % numUniqueTags
-				sheetTags = append(sheetTags, uniqueTags[tagIndex])
-			}
-
-			cheatpaths[0]["sheet"+string(rune(i))] = sheet.Sheet{
-				Title: "sheet" + string(rune(i)),
-				Tags:  sheetTags,
-			}
-		}
-
-		// Should handle large numbers efficiently
-		func() {
-			defer func() {
-				if r := recover(); r != nil {
-					t.Errorf("Tags panicked with %d unique tags, %d sheets, %d tags/sheet: %v",
-						numUniqueTags, numSheets, tagsPerSheet, r)
-				}
-			}()
-
-			result := Tags(cheatpaths)
-
-			// Should have at most numUniqueTags in result
-			if len(result) > numUniqueTags {
-				t.Errorf("More tags in result (%d) than unique tags created (%d)",
-					len(result), numUniqueTags)
-			}
-		}()
-	})
-}