Debug Counters Implementation - Clean History

Major Features:
- Debug counter infrastructure for Refill Stage tracking
- Free Pipeline counters (ss_local, ss_remote, tls_sll)
- Diagnostic counters for early return analysis
- Unified larson.sh benchmark runner with profiles
- Phase 6-3 regression analysis documentation

Bug Fixes:
- Fix SuperSlab disabled by default (HAKMEM_TINY_USE_SUPERSLAB)
- Fix profile variable naming consistency
- Add .gitignore patterns for large files

Performance:
- Phase 6-3: 4.79 M ops/s (has OOM risk)
- With SuperSlab: 3.13 M ops/s (+19% improvement)

This is a clean repository without large log files.

🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>

benchmarks/scripts/utils/lua_workload.lua

@@ -0,0 +1,25 @@
+-- lua_workload.lua - mixed string builder + table churn
+
+local N = tonumber(os.getenv("LUA_WORK_N")) or 500000
+
+-- String builder (amortized)
+local t = {}
+for i = 1, N do
+  t[#t+1] = tostring(i)
+  if (i % 5) == 0 then t[#t+1] = "-" end
+end
+local s = table.concat(t)
+
+-- Table churn (insert/remove)
+local arr = {}
+for i = 1, N do
+  arr[i] = i * 3
+end
+local sum = 0
+for i = 1, N, 3 do
+  sum = sum + (arr[i] or 0)
+  arr[i] = nil
+end
+
+print("len(s)=", #s, " sum=", sum)
+