chore: update meta_rule_usage_guide with state and override

doc/meta_rule_usage_guide.md

@@ -60,13 +60,49 @@ For complex tasks, you might combine multiple meta-rules:
 meta_core_always_on + meta_research + meta_bug_diagnosis
 ```
 
+## Workflow Flexibility: Phase-Based, Not Waterfall
+
+**Important**: Meta-rules represent **workflow phases**, not a rigid sequence. You can:
+
+### **Jump Between Phases Freely**
+- **Start with diagnosis** if you already know the problem
+- **Go back to research** if your fix reveals new issues  
+- **Switch to planning** mid-implementation if scope changes
+- **Document at any phase** - not just at the end
+
+### **Mode Switching by Invoking Meta-Rules**
+Each meta-rule invocation **automatically switches your workflow mode**:
+
+```
+Research Mode → Invoke @meta_bug_diagnosis → Diagnosis Mode
+Diagnosis Mode → Invoke @meta_bug_fixing → Fixing Mode
+Planning Mode → Invoke @meta_feature_implementation → Implementation Mode
+```
+
+### **Phase Constraints, Not Sequence Constraints**
+- **Within each phase**: Clear constraints on what you can/cannot do
+- **Between phases**: Complete freedom to move as needed
+- **No forced order**: Choose the phase that matches your current need
+
+### **Example of Flexible Workflow**
+```
+1. Start with @meta_research (investigation mode)
+2. Jump to @meta_bug_diagnosis (diagnosis mode) 
+3. Realize you need more research → back to @meta_research
+4. Complete diagnosis → @meta_bug_fixing (implementation mode)
+5. Find new issues → back to @meta_bug_diagnosis
+6. Complete fix → @meta_documentation (documentation mode)
+```
+
+**The "sticky" part means**: Each phase has clear boundaries, but you control when to enter/exit phases.
+
 ## Practical Usage Examples
 
-### **Example 1: Bug Investigation**
+### **Example 1: Bug Investigation (Flexible Flow)**
 
 **Scenario**: User reports that the contact list isn't loading properly
 
-**Meta-Rule Selection**:
+**Initial Meta-Rule Selection**:
 ```
 meta_core_always_on + meta_research + meta_bug_diagnosis
 ```
@@ -76,13 +112,15 @@ meta_core_always_on + meta_research + meta_bug_diagnosis
 - **Research**: Systematic investigation methodology, evidence collection
 - **Bug Diagnosis**: Defect analysis framework, root cause identification
 
-**Workflow**:
+**Flexible Workflow**:
 1. Apply core always-on for foundation
 2. Use research meta-rule for systematic investigation
-3. Apply bug diagnosis for defect analysis
+3. Switch to bug diagnosis when you have enough evidence
-4. Follow the bundled workflow automatically
+4. **Can go back to research** if diagnosis reveals new questions
+5. **Can jump to bug fixing** if root cause is obvious
+6. **Can document findings** at any phase
 
-### **Example 2: Feature Development**
+### **Example 2: Feature Development (Iterative Flow)**
 
 **Scenario**: Building a new contact search feature
 
@@ -96,12 +134,15 @@ meta_core_always_on + meta_feature_planning + meta_feature_implementation
 - **Feature Planning**: Requirements analysis, architecture planning
 - **Feature Implementation**: Development workflow, testing strategy
 
-**Workflow**:
+**Iterative Workflow**:
 1. Start with core always-on
 2. Use feature planning for design and requirements
 3. Switch to feature implementation for coding and testing
+4. **Can return to planning** if implementation reveals design issues
+5. **Can go back to research** if you need to investigate alternatives
+6. **Can document progress** throughout the process
 
-### **Example 3: Documentation Creation**
+### **Example 3: Documentation Creation (Parallel Flow)**
 
 **Scenario**: Writing a migration guide for the new database system
 
@@ -114,10 +155,13 @@ meta_core_always_on + meta_documentation
 - **Core Always-On**: Foundation and context
 - **Documentation**: Educational focus, templates, quality standards
 
-**Workflow**:
+**Parallel Workflow**:
 1. Apply core always-on for foundation
 2. Use documentation meta-rule for educational content creation
-3. Follow educational templates and quality standards
+3. **Can research** while documenting if you need more information
+4. **Can plan** documentation structure as you write
+5. **Can implement** examples or code snippets as needed
+6. Follow educational templates and quality standards
 
 ## Meta-Rule Application Process