feat: adjust chapter title spacing and increase section numbering depth

- Modify chapter title top spacing from 0pt to 0cm for consistency
- Set section numbering depth to 3 levels (1.1.1 format)

latex/thesis.cls

@@ -87,7 +87,10 @@
 }
 
 % Chapter formatting
-\titlespacing{\chapter}{0pt}{0pt}{*1.5}
+\titlespacing{\chapter}{0pt}{0cm}{*1.5}    % 0pt→0cm: same value, different unit
+                                             % 0pt = no space above chapter title
+                                             % *1.5 = 1.5× line spacing after title
+
 \titleformat{\chapter}[display]
   {\normalsize\bfseries\centering}
   {BAB~\Roman{chapter}} % << display format
@@ -99,6 +102,10 @@
 \titleformat{\subsection}
     {\normalsize\bfseries}{\thesubsection}{1em}{}
 
+% Section numbering depth
+\setcounter{secnumdepth}{3}               % Enables numbering for:
+                                          % 1 = chapters, 2 = sections, 3 = subsections
+
 % Ensure chapter reference in TOC matches
 \renewcommand{\cftchappresnum}{BAB~}
 \renewcommand{\cftchapaftersnum}{\quad}