refactor(main): port main from C to Zig

Makefile.cbm

@@ -72,7 +72,7 @@ CXXFLAGS_TSAN = $(CXXFLAGS_COMMON) -g -O1 \
                 -fsanitize=thread -fno-omit-frame-pointer
 
 # Windows needs ws2_32 (Winsock), psapi (GetProcessMemoryInfo), shell32
-# (CommandLineToArgvW — the UTF-8 argv path in main.c, #423/#20), ntdll
+# (CommandLineToArgvW — the UTF-8 argv path in main.zig, #423/#20), ntdll
 # (Zig's Windows runtime), and --allow-multiple-definition (MinGW CRT clashes).
 # Auto-detected via compiler; no manual override needed.
 IS_MINGW := $(shell echo | $(CC) -dM -E - 2>/dev/null | grep -q 'define _WIN32 ' && echo yes || echo no)
@@ -430,7 +430,7 @@ endif
 CBM_ZIG_SRC = src/cbm_zig.zig
 CBM_ZIG_SRCS = $(CBM_ZIG_SRC) src/cbm_zig_c.h src/cli_zig/cbm_cli_zig.zig src/cli/cli_zig.h \
                src/cli/archive.zig src/cli/cli.zig src/cli/commands.zig src/cli/store.zig \
-               src/cli/tool_args.zig \
+               src/cli/tool_args.zig src/main.zig src/main.h \
                src/cli/hook_augment.zig src/cli/progress_sink.zig src/cli/progress_sink.h \
                src/cli/cli.h src/mcp/mcp.h src/pipeline/pipeline.h \
                src/pipeline/worker_pool.h \

src/cbm_zig.zig

@@ -53,6 +53,7 @@ comptime {
     checkExports(@import("foundation/yaml.zig"));
     checkExports(@import("git/git_context.zig"));
     checkExports(@import("graph_buffer/graph_buffer.zig"));
+    checkExports(@import("main.zig"));
     checkExports(@import("mcp/code_tools.zig"));
     checkExports(@import("mcp/graph_tools.zig"));
     checkExports(@import("mcp/index_supervisor.zig"));

src/cbm_zig_c.h

@@ -40,6 +40,9 @@
 #include <io.h>
 #include <process.h>
 #include <psapi.h>
+#include <shellapi.h> /* CommandLineToArgvW: not in windows.h under WIN32_LEAN_AND_MEAN */
+#include <signal.h>
+#include <tlhelp32.h>
 #include "foundation/win_utf8.h"
 #include <tre/regex.h>
 #else
@@ -181,6 +184,7 @@ static inline FILE *cbm_zig_stderr(void) {
 #include "discover/userconfig.h"
 #include "git/git_context.h"
 #include "graph_buffer/graph_buffer.h"
+#include "main.h"
 #include "mcp/index_supervisor.h"
 #include "pipeline/laravel_routing.h"
 #include "pipeline/lsp_resolve.h"

src/cli/cli.h

@@ -328,7 +328,7 @@ int cbm_config_delete(cbm_config_t *cfg, const char *key);
 #define CBM_CONFIG_AUTO_INDEX_LIMIT "auto_index_limit"
 #define CBM_CONFIG_AUTO_WATCH "auto_watch"
 
-/* ── Subcommands (wired from main.c) ─────────────────────────── */
+/* ── Subcommands (wired from main.zig) ─────────────────────────── */
 
 /* install: copy binary, install skills, install editor MCP configs, ensure PATH.
  * Prompts to delete old indexes if any exist — rejects on "no". */

src/foundation/profile.h

@@ -2,7 +2,7 @@
  * profile.h — Activatable fine-grained performance profiling.
  *
  * Enable via environment variable: CBM_PROFILE=1 (or any non-empty non-"0" value)
- * Init is called once at program startup (from main.c).
+ * Init is called once at program startup (from main.zig).
  *
  * When disabled (default), the CBM_PROF_* macros cost one load + branch,
  * effectively zero overhead.