Fix test compilation errors

- Make CATEGORY_* constants public in fluff_rules
- Fix fix_suggestion_t structure usage in test_diagnostics.f90
- Add missing count() and has_errors() methods to diagnostic_collection_t
- Rename count() to get_count() to avoid name conflict with field
- Fix string_array_t type usage in test_intelligent_caching.f90

All tests now compile successfully. Some linking errors remain due to
missing LSP implementations, but compilation phase is fixed.

Author: krystophny

src/fluff_diagnostics/fluff_diagnostics.f90

@@ -84,6 +84,8 @@ module fluff_diagnostics
         procedure :: to_json => collection_to_json
         procedure :: to_sarif => collection_to_sarif
         procedure :: get_stats => collection_get_stats
+        procedure :: get_count => collection_count
+        procedure :: has_errors => collection_has_errors
     end type diagnostic_collection_t
 
     ! Public procedures
@@ -736,6 +738,28 @@ function collection_get_stats(this) result(stats)
         stats = this%stats
     end function collection_get_stats
 
+    ! Get count of diagnostics in collection
+    function collection_count(this) result(count)
+        class(diagnostic_collection_t), intent(in) :: this
+        integer :: count
+        count = this%count
+    end function collection_count
+    
+    ! Check if collection has error-level diagnostics
+    function collection_has_errors(this) result(has_errors)
+        class(diagnostic_collection_t), intent(in) :: this
+        logical :: has_errors
+        integer :: i
+        
+        has_errors = .false.
+        do i = 1, this%count
+            if (this%diagnostics(i)%severity == SEVERITY_ERROR) then
+                has_errors = .true.
+                return
+            end if
+        end do
+    end function collection_has_errors
+    
     ! Helper functions for string conversion
     function int_to_string(val) result(str)
         integer, intent(in) :: val

src/fluff_rules/fluff_rules.f90

@@ -20,6 +20,9 @@ module fluff_rules
     public :: get_performance_rules
     public :: get_correctness_rules
 
+    ! Public constants
+    public :: CATEGORY_STYLE, CATEGORY_PERFORMANCE, CATEGORY_CORRECTNESS
+    
 contains
 
     ! Get all built-in rules

test/test_diagnostics.f90

@@ -99,7 +99,7 @@ subroutine test_diagnostic_collection(error)
         call collection%add(diag1)
         call collection%add(diag2)
 
-        call check(error, collection%count() == 2, "Collection should have 2 diagnostics")
+        call check(error, collection%get_count() == 2, "Collection should have 2 diagnostics")
         if (allocated(error)) return
 
         call check(error, collection%has_errors(), "Collection should have errors")
@@ -109,22 +109,29 @@ end subroutine test_diagnostic_collection
     subroutine test_fix_suggestion(error)
         type(error_type), allocatable, intent(out) :: error
         type(fix_suggestion_t) :: fix
+        type(text_edit_t) :: edit
         type(source_range_t) :: loc
 
         loc%start%line = 5
         loc%start%column = 1
         loc%end%line = 5
         loc%end%column = 20
 
+        ! Create text edit
+        edit%range = loc
+        edit%new_text = "implicit none"
+        
+        ! Create fix with proper structure
         fix%description = "Add implicit none"
-        fix%location = loc
-        fix%replacement = "implicit none"
+        allocate(fix%edits(1))
+        fix%edits(1) = edit
+        fix%is_safe = .true.
 
         call check(error, fix%description == "Add implicit none", &
             "Fix description should match")
         if (allocated(error)) return
 
-        call check(error, fix%replacement == "implicit none", &
+        call check(error, fix%edits(1)%new_text == "implicit none", &
             "Fix replacement should match")
 
     end subroutine test_fix_suggestion

test/test_intelligent_caching.f90

@@ -652,14 +652,14 @@ end function test_dependency_invalidation
     function test_cross_file_dependencies() result(success)
         logical :: success
         type(analysis_cache_t) :: cache
-        character(len=:), allocatable :: affected_files(:)
+        type(string_array_t) :: affected_files
 
         cache = create_analysis_cache()
         call cache%add_dependency("file1.f90", "common.f90")
         call cache%add_dependency("file2.f90", "common.f90")
 
         affected_files = cache%get_files_depending_on("common.f90")
-        success = size(affected_files) == 2
+        success = affected_files%count == 2
 
     end function test_cross_file_dependencies