docs: add v0.4.0 changelog, update to v0.6.0

CHANGELOG.md

@@ -2,6 +2,16 @@
 
 All notable changes to ArcheFlow are documented in this file.
 
+## [0.6.0] -- 2026-04-04
+
+### Added
+- Expanded attention-filters skill with prompt templates, token budgets, cycle-back filtering, and verification checklist
+- Explorer skip heuristic in plan-phase with decision table for when to skip/require research
+- Runnable quickstart example (`examples/runnable-quickstart.md`)
+
+### Fixed
+- Normalized agent persona frontmatter: added examples, moved isolation note to Rules, documented model choices
+
 ## [0.5.0] -- 2026-04-04
 
 ### Added
@@ -12,6 +22,19 @@ All notable changes to ArcheFlow are documented in this file.
 - Cross-run finding regression detection in `archeflow-memory.sh` — compares current findings against previously resolved fixes
 - Check-phase parallel reviewer spawning protocol with Guardian-first sequence, A2 fast-path evaluation, timeout handling, and re-check protocol
 
+## [0.4.0] -- 2026-04-04
+
+### Added
+- Confidence gate parsing with bash snippets for extracting scores from `plan-creator.md`
+- Mini-Explorer spawning when risk coverage < 0.5
+- Worktree merge flow with explicit pre-merge hooks and post-merge test validation
+- `archeflow-rollback.sh` for post-merge test failure auto-revert
+- Test-first validation gate in Do phase
+- Memory injection audit trail with `--audit` flag and `audit-check` command
+
+### Fixed
+- Unified feedback routing tables across orchestration, act-phase, artifact-routing
+
 ## [0.3.0] -- 2026-04-03
 
 ### Added