hardening: implement sql_buffer_t, refactor bulk queries, and add test suite (#466)

Rebased onto develop after #514 merge. Resolved 13 conflicts in
poller.c by preserving the conditional output_regex detection
(regex_col) from #514 instead of hardcoded column references.

Signed-off-by: Thomas Vincent <thomasvincent@gmail.com>

Author: somethingwithproof

.github/warning-baseline.txt

@@ -0,0 +1 @@
+0

.gitignore

@@ -19,7 +19,9 @@
 # | http://www.cacti.net/                                                   |
 # +-------------------------------------------------------------------------+
 
+# Build Artifacts
 .deps
+.libs
 Makefile
 Makefile.in
 configure
@@ -28,5 +30,22 @@ autom4te.cache/
 config/
 libtool
 /spine
+/spine-conf
 *.o
+*.lo
+*.la
 *.m4
+.dirstamp
+
+# Project/IDE specific patterns and local worktrees to ensure repository hygiene
+.worktrees/
+.omc/
+.DS_Store
+*.swp
+*.log
+*~
+# Sanitizer logs
+asan.*
+ubsan.*
+tsan.*
+valgrind.*

Makefile.am

@@ -33,7 +33,14 @@ man_MANS = spine.1
 
 EXTRA_DIST = spine.1 uthash.h
 
-# Docker targets — require Dockerfile and Dockerfile.dev (from PR #401)
+# Unit tests (standalone, no spine build required)
+TESTS = tests/unit/test_sql_buffer
+check_PROGRAMS = tests/unit/test_sql_buffer
+tests_unit_test_sql_buffer_SOURCES = tests/unit/test_sql_buffer.c
+tests_unit_test_sql_buffer_CFLAGS = -I$(top_srcdir) $(CMOCKA_CFLAGS)
+tests_unit_test_sql_buffer_LDADD = $(CMOCKA_LIBS)
+
+# Docker targets
 .PHONY: docker docker-dev verify cppcheck
 
 docker: