refactor(cli): change from env var injection to direct prompt concatenation

- Replace $PROTO/$TMPL environment variable injection with systemRules/roles direct concatenation
- Append rules to END of prompt instead of prepending
- Change prompt field name from RULES to CONSTRAINTS in all prompts
- Default to universal-rigorous-style template when --rule not specified
- Update all .claude documentation, agents, commands, and skills
- Add streaming_content type support for Gemini delta messages

Breaking: Prompts now use CONSTRAINTS field instead of RULES

.claude/commands/workflow/lite-execute.md

@@ -486,7 +486,7 @@ TASK: • Verify plan acceptance criteria fulfillment • Analyze code quality
 MODE: analysis
 CONTEXT: @**/* @{plan.json} [@{exploration.json}] | Memory: Review lite-execute changes against plan requirements
 EXPECTED: Quality assessment with acceptance criteria verification, issue identification, and recommendations. Explicitly check each acceptance criterion from plan.json tasks.
-RULES: $PROTO $TMPL | Focus on plan acceptance criteria and plan adherence | analysis=READ-ONLY
+CONSTRAINTS: Focus on plan acceptance criteria and plan adherence | analysis=READ-ONLY
 ```
 
 **Tool-Specific Execution** (Apply shared prompt template above):

.claude/commands/workflow/lite-lite-lite.md

@@ -167,7 +167,7 @@ TASK: ${tasks.map(t => `• ${t}`).join(' ')}
 MODE: analysis
 CONTEXT: @**/*
 EXPECTED: ${expected}
-RULES: $PROTO | ${rules}
+CONSTRAINTS: ${rules}
 `
 }
 
@@ -373,7 +373,7 @@ TASK: ${extractedTasks.join(' • ')}
 MODE: write
 CONTEXT: @${affectedFiles.join(' @')}
 EXPECTED: Working implementation with all changes applied
-RULES: $PROTO
+CONSTRAINTS: Follow existing patterns
 " --tool ${executionTool.name} --mode write`,
     run_in_background: false
   })

.claude/commands/workflow/tools/conflict-resolution.md

@@ -154,7 +154,7 @@ Task(subagent_type="cli-execution-agent", run_in_background=false, prompt=`
     - Validation of exploration conflict_indicators
     - ModuleOverlap conflicts with overlap_analysis
     - Targeted clarification questions
-  RULES: $PROTO $TMPL | Focus on breaking changes, migration needs, and functional overlaps | Prioritize exploration-identified conflicts | analysis=READ-ONLY
+  CONSTRAINTS: Focus on breaking changes, migration needs, and functional overlaps | Prioritize exploration-identified conflicts | analysis=READ-ONLY
   " --tool gemini --mode analysis --rule analysis-code-patterns --cd {project_root}
 
   Fallback: Qwen (same prompt) → Claude (manual analysis)