refactor(docs): move core docs into framework/business/research (move-only)

- framework/: principles, rules, flags (思想・行動規範)
- business/: symbols, examples (ビジネス領域)
- research/: config (調査設定)
- All files renamed to lowercase for consistency

docs/memory/tasks/README.md

@@ -0,0 +1,55 @@
+# Task Memory Index
+
+This directory contains documentation of completed tasks, tracked by PM Agent.
+
+## Purpose
+
+- **Knowledge Capture**: Preserve implementation patterns and decisions
+- **Learning Archive**: Accumulate project-specific learnings
+- **Searchable History**: Grep-friendly task records
+
+## Structure
+
+```
+tasks/
+├── README.md (this file)
+├── 2025-10-17-auth-implementation.md
+├── 2025-10-17-api-redesign.md
+└── [date]-[task-name].md
+```
+
+## Naming Convention
+
+```
+[YYYY-MM-DD]-[kebab-case-description].md
+```
+
+Examples:
+- `2025-10-17-jwt-auth.md`
+- `2025-10-18-database-migration.md`
+- `2025-10-20-performance-optimization.md`
+
+## Task File Template
+
+See `superclaude/agents/pm-agent/workflows/task-management.md` for the standard template.
+
+## Maintenance
+
+**PM Agent Monthly Review**:
+1. Prune outdated tasks (>6 months old)
+2. Extract patterns to `docs/patterns/`
+3. Update this index
+4. Archive old tasks to `tasks/archive/` if needed
+
+## Search Examples
+
+```bash
+# Find all authentication-related tasks
+grep -r "auth" docs/memory/tasks/
+
+# Find tasks with specific patterns
+grep -r "middleware composition" docs/memory/tasks/
+
+# List recent tasks
+ls -lt docs/memory/tasks/ | head -10
+```