chore(openspec): drop 9 superseded proposals + 11 stub archive files

Drop 9 batch proposals that are superseded by the boocode-lift-analysis
(boocontext-audit, conductor upgrades, self-healing/verify-gate skills):
add-3tier-memory, import-llm-evaluator, import-pregel-engine, plugin-platform,
conductor-evolution, code-intelligence-upgrade, dev-workflow, ui-overhaul,
agent-reliability.

Delete 11 stub archive files (49-66B each, 'Status: Shipped. Archived.' only)
that provide zero documentation value over the existing CHANGELOG.md + git tags.

openspec/changes/add-behavioral-engine/specs/guideline-model/spec.md

@@ -0,0 +1,17 @@
+## ADDED Requirements
+
+### Requirement: Guideline creation
+- **WHEN** creating a guideline with condition, action, and criticality
+- **THEN** it is stored with unique ID and metadata
+
+### Requirement: Guideline evaluation
+- **WHEN** an agent action triggers guideline evaluation
+- **THEN** matching guidelines are activated with score and rationale
+
+### Requirement: Criticality levels
+- **WHEN** evaluating guidelines
+- **THEN** guidelines are filtered by criticality (low/medium/high/critical) with higher-criticality taking precedence
+
+#### Scenario: Security policy enforcement
+- **WHEN** an agent attempts to edit a file matching a security guideline condition
+- **THEN** the guideline matcher returns the relevant rule with CRITICAL severity