refactor: move bundled skills tree to repo root skills/

- Relocate runtime/skills -> skills/; runtime_skills_root() prefers oclaw/skills
  with fallback to legacy runtime/skills for unmigrated trees.
- session-bootstrap hook handler resolves repo root via PROJECT_ROOT.
- Update architecture/migration docs and in-tree skill references.

Co-authored-by: Cursor <cursoragent@cursor.com>

skills/self-improvement/assets/LEARNINGS.md

@@ -0,0 +1,45 @@
+# Learnings
+
+Corrections, insights, and knowledge gaps captured during development.
+
+**Categories**: correction | insight | knowledge_gap | best_practice
+**Areas**: frontend | backend | infra | tests | docs | config
+**Statuses**: pending | in_progress | resolved | wont_fix | promoted | promoted_to_skill
+
+## Status Definitions
+
+| Status | Meaning |
+|--------|---------|
+| `pending` | Not yet addressed |
+| `in_progress` | Actively being worked on |
+| `resolved` | Issue fixed or knowledge integrated |
+| `wont_fix` | Decided not to address (reason in Resolution) |
+| `promoted` | Elevated to CLAUDE.md, AGENTS.md, or copilot-instructions.md |
+| `promoted_to_skill` | Extracted as a reusable skill |
+
+## Skill Extraction Fields
+
+When a learning is promoted to a skill, add these fields:
+
+```markdown
+**Status**: promoted_to_skill
+**Skill-Path**: skills/skill-name
+```
+
+Example:
+```markdown
+## [LRN-20250115-001] best_practice
+
+**Logged**: 2025-01-15T10:00:00Z
+**Priority**: high
+**Status**: promoted_to_skill
+**Skill-Path**: skills/docker-m1-fixes
+**Area**: infra
+
+### Summary
+Docker build fails on Apple Silicon due to platform mismatch
+...
+```
+
+---
+