docs: add Doxygen configuration file

- Create comprehensive Doxyfile for API documentation generation
- Configure for SQL file parsing (treated as C++ for Doxygen)
- Enable HTML output to docs/api directory
- Exclude test files and build artifacts
- Add docs/api/ to .gitignore for generated documentation

To generate documentation:
  doxygen Doxyfile

Output will be in docs/api/html/index.html

Author: tobyhede

.gitignore

@@ -13,6 +13,9 @@ deps-ordered-supabase.txt
 
 src/version.sql
 
+# Doxygen generated documentation
+docs/api/
+
 
 
 # Logs

Doxyfile

@@ -0,0 +1,140 @@
+# Doxyfile for Encrypt Query Language (EQL)
+# PostgreSQL extension for searchable encryption
+
+#---------------------------------------------------------------------------
+# Project Settings
+#---------------------------------------------------------------------------
+
+PROJECT_NAME           = "Encrypt Query Language (EQL)"
+PROJECT_NUMBER         = "2.x"
+PROJECT_BRIEF          = "PostgreSQL extension for searchable encryption"
+PROJECT_LOGO           =
+
+OUTPUT_DIRECTORY       = docs/api
+CREATE_SUBDIRS         = NO
+
+#---------------------------------------------------------------------------
+# Build Settings
+#---------------------------------------------------------------------------
+
+GENERATE_HTML          = YES
+GENERATE_LATEX         = NO
+GENERATE_XML           = NO
+GENERATE_MAN           = NO
+
+HTML_OUTPUT            = html
+HTML_FILE_EXTENSION    = .html
+HTML_COLORSTYLE_HUE    = 220
+HTML_COLORSTYLE_SAT    = 100
+HTML_COLORSTYLE_GAMMA  = 80
+HTML_TIMESTAMP         = YES
+HTML_DYNAMIC_SECTIONS  = YES
+
+#---------------------------------------------------------------------------
+# Input Settings
+#---------------------------------------------------------------------------
+
+INPUT                  = src/
+FILE_PATTERNS          = *.sql *.template
+RECURSIVE              = YES
+EXCLUDE_PATTERNS       = *_test.sql \
+                         */release/* \
+                         */tests/* \
+                         .git/* \
+                         */.worktrees/*
+
+# Treat SQL files as C++ for parsing
+EXTENSION_MAPPING      = sql=C++ template=C++
+
+#---------------------------------------------------------------------------
+# Extraction Settings
+#---------------------------------------------------------------------------
+
+EXTRACT_ALL            = NO
+EXTRACT_PRIVATE        = NO
+EXTRACT_STATIC         = YES
+EXTRACT_LOCAL_CLASSES  = YES
+EXTRACT_ANON_NSPACES   = NO
+
+HIDE_UNDOC_MEMBERS     = NO
+HIDE_UNDOC_CLASSES     = NO
+HIDE_IN_BODY_DOCS      = NO
+
+#---------------------------------------------------------------------------
+# Preprocessing
+#---------------------------------------------------------------------------
+
+ENABLE_PREPROCESSING   = NO
+MACRO_EXPANSION        = NO
+EXPAND_ONLY_PREDEF     = NO
+
+#---------------------------------------------------------------------------
+# Documentation Settings
+#---------------------------------------------------------------------------
+
+JAVADOC_AUTOBRIEF      = YES
+QT_AUTOBRIEF           = NO
+MULTILINE_CPP_IS_BRIEF = NO
+
+TAB_SIZE               = 2
+OPTIMIZE_OUTPUT_FOR_C  = YES
+OPTIMIZE_OUTPUT_JAVA   = NO
+
+BUILTIN_STL_SUPPORT    = NO
+CPP_CLI_SUPPORT        = NO
+SIP_SUPPORT            = NO
+IDL_PROPERTY_SUPPORT   = YES
+
+#---------------------------------------------------------------------------
+# Warning and Progress Settings
+#---------------------------------------------------------------------------
+
+QUIET                  = NO
+WARNINGS               = YES
+WARN_IF_UNDOCUMENTED   = YES
+WARN_IF_DOC_ERROR      = YES
+WARN_NO_PARAMDOC       = YES
+WARN_AS_ERROR          = NO
+WARN_FORMAT            = "$file:$line: $text"
+
+#---------------------------------------------------------------------------
+# Source Browsing
+#---------------------------------------------------------------------------
+
+SOURCE_BROWSER         = YES
+INLINE_SOURCES         = NO
+STRIP_CODE_COMMENTS    = NO
+REFERENCED_BY_RELATION = YES
+REFERENCES_RELATION    = YES
+VERBATIM_HEADERS       = YES
+
+#---------------------------------------------------------------------------
+# Alphabetical Index
+#---------------------------------------------------------------------------
+
+ALPHABETICAL_INDEX     = YES
+COLS_IN_ALPHA_INDEX    = 5
+
+#---------------------------------------------------------------------------
+# Graph Generation
+#---------------------------------------------------------------------------
+
+HAVE_DOT               = NO
+CLASS_DIAGRAMS         = NO
+COLLABORATION_GRAPH    = NO
+GROUP_GRAPHS           = NO
+INCLUDE_GRAPH          = NO
+INCLUDED_BY_GRAPH      = NO
+CALL_GRAPH             = NO
+CALLER_GRAPH           = NO
+GRAPHICAL_HIERARCHY    = NO
+DIRECTORY_GRAPH        = NO
+DOT_IMAGE_FORMAT       = png
+INTERACTIVE_SVG        = NO
+
+#---------------------------------------------------------------------------
+# Search Engine
+#---------------------------------------------------------------------------
+
+SEARCHENGINE           = YES
+SERVER_BASED_SEARCH    = NO