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/sqlite_workload.sql

@@ -0,0 +1,32 @@
+PRAGMA journal_mode = OFF;
+PRAGMA synchronous = OFF;
+PRAGMA temp_store = MEMORY;
+
+-- schema
+CREATE TABLE t (
+  id INTEGER PRIMARY KEY,
+  s  TEXT
+);
+
+-- bulk insert via recursive CTE (~50k rows)
+WITH RECURSIVE cnt(x) AS (
+  SELECT 1
+  UNION ALL
+  SELECT x+1 FROM cnt LIMIT 50000
+)
+INSERT INTO t(s)
+SELECT printf('str-%d-%d', x, x*x) FROM cnt;
+
+-- simple read queries
+SELECT COUNT(*) FROM t;
+SELECT SUM(LENGTH(s)) FROM t;
+
+-- point lookups
+SELECT s FROM t WHERE id IN (1, 100, 1000, 10000, 40000);
+
+-- update a slice
+UPDATE t SET s = s || '-x' WHERE (id % 50) = 0;
+
+-- final check
+SELECT COUNT(*) FROM t WHERE s LIKE '%-x';
+