Optimize C6 heavy and C7 ultra performance analysis with refined design refinements

- Update environment profile presets and visibility analysis
- Enhance small object and tiny segment v4 box implementations
- Refine C7 ultra and C6 heavy allocation strategies
- Add comprehensive performance metrics and design documentation

🤖 Generated with Claude Code

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

core/hakmem_tiny.c

@@ -83,6 +83,8 @@ void tiny_front_v3_snapshot_init(void) {
         .header_mode = (uint8_t)tiny_header_mode(),
         .header_v3_enabled = tiny_header_v3_enabled(),
         .header_v3_skip_c7 = tiny_header_v3_skip_c7(),
+        .c7_ultra_enabled = tiny_c7_ultra_enabled_env(),
+        .c7_ultra_header_light = tiny_c7_ultra_header_light_enabled_env(),
     };
     g_tiny_front_v3_snapshot = snap;
     g_tiny_front_v3_snapshot_ready = 1;